## digitalmars.D - Low dimensional matrices, vectors, quaternions and a cubic equation

- "Gareth Charnock" <gareth.charnock gmail.com> Apr 15 2010
- bearophile <bearophileHUGS lycos.com> Apr 15 2010
- Johan Granberg <lijat.meREM OVEgmail.com> Apr 15 2010
- Andrei Alexandrescu <SeeWebsiteForEmail erdani.org> Apr 15 2010
- Gareth Charnock <gareth.tpc gmail.com> Apr 16 2010
- Andrei Alexandrescu <SeeWebsiteForEmail erdani.org> Apr 16 2010
- Gareth Charnock <gareth.tpc gmail.com> Apr 18 2010
- #ponce <spam spam.spam> Apr 19 2010
- "Lars T. Kyllingstad" <public kyllingen.NOSPAMnet> Apr 19 2010
- "Lars T. Kyllingstad" <public kyllingen.NOSPAMnet> Apr 19 2010
- Eric Poggel <dnewsgroup yage3d.net> Apr 19 2010
- Eric Poggel <dnewsgroup yage3d.net> Apr 19 2010
- Eric Poggel <dnewsgroup yage3d.net> Apr 19 2010
- Andrei Alexandrescu <SeeWebsiteForEmail erdani.org> Apr 19 2010
- Clemens <eriatarka84 gmail.com> Apr 20 2010
- #ponce <spam spam.spam> Apr 20 2010
- Gareth Charnock <gareth.tpc gmail.com> Apr 20 2010
- "Simen kjaeraas" <simen.kjaras gmail.com> Apr 16 2010
- "Simen kjaeraas" <simen.kjaras gmail.com> Apr 16 2010
- Philippe Sigaud <philippe.sigaud gmail.com> Apr 18 2010
- Fawzi Mohamed <fawzi gmx.ch> Apr 19 2010
- BLS <windevguy hotmail.de> Apr 15 2010
- "Lars T. Kyllingstad" <public kyllingen.NOSPAMnet> Apr 16 2010
- Gareth Charnock <gareth.tpc gmail.com> Apr 16 2010
- "Robert Jacques" <sandford jhu.edu> Apr 15 2010
- Fawzi Mohamed <fawzi gmx.ch> Apr 16 2010
- "Robert Jacques" <sandford jhu.edu> Apr 16 2010

As a side effect of my PhD project I've got a collection of mathematical classes. I'd be happy to collect them together, tidy them up and donate them to phobos the authors are interested in including them. Matrices and vectors in particular get reinvented all the time so I'm sure users of D will appreciate them being there. Quaternions are probably somewhat more specialised; they are most often used for representing rotations (they have different advantages and disadvantages to rotation matrices). I've also written a solver for cubic equations. The matrix and vector classes are of the sort where the dimension is known at compile time and will probably be most useful for modelling geometry. High dimensional matrices and vectors are probably better left to a scientific library (I remember there was talk that one might be being proposed). Would this sort of functionality be useful for phobos? At the moment, I can't promise anything, I'm just trying to judge the interest should I find time to look into it. Gareth Charnock

Apr 15 2010

Gareth Charnock:Matrices and vectors in particular get reinvented all the time so I'm sure users of D will appreciate them being there.

I've seen so many times people re-write a 2D-3D vector struct that I hope it will be added to Phobos once and for all. Bye, bearophile

Apr 15 2010

bearophile wrote:Gareth Charnock:Matrices and vectors in particular get reinvented all the time so I'm sure users of D will appreciate them being there.

I've seen so many times people re-write a 2D-3D vector struct that I hope it will be added to Phobos once and for all. Bye, bearophile

Quaternions to by the way.

Apr 15 2010

On 04/15/2010 01:49 PM, Gareth Charnock wrote:As a side effect of my PhD project I've got a collection of mathematical classes. I'd be happy to collect them together, tidy them up and donate them to phobos the authors are interested in including them. Matrices and vectors in particular get reinvented all the time so I'm sure users of D will appreciate them being there. Quaternions are probably somewhat more specialised; they are most often used for representing rotations (they have different advantages and disadvantages to rotation matrices). I've also written a solver for cubic equations. The matrix and vector classes are of the sort where the dimension is known at compile time and will probably be most useful for modelling geometry. High dimensional matrices and vectors are probably better left to a scientific library (I remember there was talk that one might be being proposed). Would this sort of functionality be useful for phobos? At the moment, I can't promise anything, I'm just trying to judge the interest should I find time to look into it. Gareth Charnock

I think it would. Could you please post a brief list of features so people can take a look? Andrei

Apr 15 2010

Okay, here goes. I've collected together the basic functionality that would probably make a good starting point. As I've mentioned my code is very messy and has bits missing (e.g. I never had a use for the cross product but it's pretty important in general). I guess a good way to begin would be to write the pubic interfaces then start on the implementation. Cubic Solvers: General complex cubic solver with two algorithms (one requiring a complex cosine and and arcosine one using only +-*/ and roots). A special case cubic solver for the reduced cubic x^^3 + px - q = 0. Quaternions: opAdd, opSub, opMult(quaternion), opMult(vector), opDiv, Normalise, Normalized, conjugate, conjugated, toEulerAngles*, fromEulerAngles, this(real,i,j,k), this(angle,axis), getAngle(), getAxis() *Currently I've only got a quaternion->euler angles routine that works in the ZYZ convention but I have read a paper that generalises my method to all valid axis conventions. Will probably impliment as something like: toEulerAngles(string convention="XYZ")() Vectors: opAdd, opSub, opMult(scalar), opMult(vector)*, cross**, Normalise, Normalized, Length * dot product. Would this be better named as dot()? ** 3D vectors only. Perhaps defining a cross product on the Matrices: opAdd, opSub, opMult(scalar), opMult(vector), opMult(matrix)**, Invert, Inverted, Orthogonalize, Orthogonalized, Reorthogonalize***, Reorthogonalized***, Det, Transpose, Transposed, Dagger*, Daggered*, Eigenvalues****, Eigenvectors**** *The hermitian conjugate/conjugate transpose. Reduces to the transpose for a real matrix ** Matrix-matrix multiplication doesn't commute. Could this be a problem when using operator notation? *** Othogonalize assuming the matrix is nearly orthogonal already (possibly using some quick, approximate method such as a Taylor series) **** I have a eigenvalue/vector solver for 3x3 matrices which seems reasonably stable but needs more testing. Free functions: MatrixToQuaternion QuaternionToMatrix + code to allow easy printing to stdout/streams and such. Andrei Alexandrescu wrote:On 04/15/2010 01:49 PM, Gareth Charnock wrote:As a side effect of my PhD project I've got a collection of mathematical classes. I'd be happy to collect them together, tidy them up and donate them to phobos the authors are interested in including them. Matrices and vectors in particular get reinvented all the time so I'm sure users of D will appreciate them being there. Quaternions are probably somewhat more specialised; they are most often used for representing rotations (they have different advantages and disadvantages to rotation matrices). I've also written a solver for cubic equations. The matrix and vector classes are of the sort where the dimension is known at compile time and will probably be most useful for modelling geometry. High dimensional matrices and vectors are probably better left to a scientific library (I remember there was talk that one might be being proposed). Would this sort of functionality be useful for phobos? At the moment, I can't promise anything, I'm just trying to judge the interest should I find time to look into it. Gareth Charnock

I think it would. Could you please post a brief list of features so people can take a look? Andrei

Apr 16 2010

On 04/16/2010 04:25 PM, Gareth Charnock wrote:Okay, here goes. I've collected together the basic functionality that would probably make a good starting point. As I've mentioned my code is very messy and has bits missing (e.g. I never had a use for the cross product but it's pretty important in general). I guess a good way to begin would be to write the pubic interfaces then start on the implementation. Cubic Solvers: General complex cubic solver with two algorithms (one requiring a complex cosine and and arcosine one using only +-*/ and roots). A special case cubic solver for the reduced cubic x^^3 + px - q = 0.

This sounds a candidate for std.numeric. How popular/needed are cubic solvers?Quaternions: opAdd, opSub, opMult(quaternion), opMult(vector), opDiv, Normalise, Normalized, conjugate, conjugated, toEulerAngles*, fromEulerAngles, this(real,i,j,k), this(angle,axis), getAngle(), getAxis()

Sounds good, but you'd need to convert the code to the new overloaded operators approach.*Currently I've only got a quaternion->euler angles routine that works in the ZYZ convention but I have read a paper that generalises my method to all valid axis conventions. Will probably impliment as something like: toEulerAngles(string convention="XYZ")() Vectors: opAdd, opSub, opMult(scalar), opMult(vector)*, cross**, Normalise, Normalized, Length

What is the representation of vectors? I'm afraid the design above would be too limited for what we need.* dot product. Would this be better named as dot()?

We already have dot product and normalization routines that work with general ranges. http://www.digitalmars.com/d/2.0/phobos/std_numeric.html#dotProduct http://www.digitalmars.com/d/2.0/phobos/std_numeric.html#normalize Generally I'd strongly suggest making operations free generic functions instead of members.** 3D vectors only. Perhaps defining a cross product on the Matrices: opAdd, opSub, opMult(scalar), opMult(vector), opMult(matrix)**, Invert, Inverted, Orthogonalize, Orthogonalized, Reorthogonalize***, Reorthogonalized***, Det, Transpose, Transposed, Dagger*, Daggered*, Eigenvalues****, Eigenvectors****

What is the representation of matrices?*The hermitian conjugate/conjugate transpose. Reduces to the transpose for a real matrix

Transposition should also be handled in a static manner, e.g. define a transposed view of a matrix that doesn't actually move elements.** Matrix-matrix multiplication doesn't commute. Could this be a problem when using operator notation?

Should be fine.*** Othogonalize assuming the matrix is nearly orthogonal already (possibly using some quick, approximate method such as a Taylor series) **** I have a eigenvalue/vector solver for 3x3 matrices which seems reasonably stable but needs more testing. Free functions: MatrixToQuaternion QuaternionToMatrix + code to allow easy printing to stdout/streams and such.

Sounds encouraging. I think a good next step is to go through a community scrutiny process by dropping the code somewhere on the Web so people can review it. Andrei

Apr 16 2010

Andrei Alexandrescu wrote:On 04/16/2010 04:25 PM, Gareth Charnock wrote:Okay, here goes. I've collected together the basic functionality that would probably make a good starting point. As I've mentioned my code is very messy and has bits missing (e.g. I never had a use for the cross product but it's pretty important in general). I guess a good way to begin would be to write the pubic interfaces then start on the implementation. Cubic Solvers: General complex cubic solver with two algorithms (one requiring a complex cosine and and arcosine one using only +-*/ and roots). A special case cubic solver for the reduced cubic x^^3 + px - q = 0.

This sounds a candidate for std.numeric. How popular/needed are cubic solvers?

They're probably don't come up that frequently but they do they're rather fiddly. Lots of operations to get right. But the solution doesn't depend on anything but basic math operators so once it's written, it's written. I guess the question is whether Phobos is meant to be a small library or a kitchen sink library.Quaternions: opAdd, opSub, opMult(quaternion), opMult(vector), opDiv, Normalise, Normalized, conjugate, conjugated, toEulerAngles*, fromEulerAngles, this(real,i,j,k), this(angle,axis), getAngle(), getAxis()

Sounds good, but you'd need to convert the code to the new overloaded operators approach.

Fair enough, and this will be a good opportunity to show off why the new overloading scheme is more powerful (e.g. opAdd and opSub can be combined).*Currently I've only got a quaternion->euler angles routine that works in the ZYZ convention but I have read a paper that generalises my method to all valid axis conventions. Will probably impliment as something like: toEulerAngles(string convention="XYZ")() Vectors: opAdd, opSub, opMult(scalar), opMult(vector)*, cross**, Normalise, Normalized, Length

What is the representation of vectors? I'm afraid the design above would be too limited for what we need.

vector is defined over is templated. What other operators are needed? I'd defiantly want to add swizzling. http://www.ogre3d.org/docs/api/html/classOgre_1_1Vector3.html looks like it could be a good source of ideas.* dot product. Would this be better named as dot()?

We already have dot product and normalization routines that work with general ranges. http://www.digitalmars.com/d/2.0/phobos/std_numeric.html#dotProduct http://www.digitalmars.com/d/2.0/phobos/std_numeric.html#normalize Generally I'd strongly suggest making operations free generic functions instead of members.

I've not really thought about operators as members vs operators as free functions. I just tend to put them as members because it feels more organised. But looking at other implementations, I seem to be in the minority.** 3D vectors only. Perhaps defining a cross product on the Matrices: opAdd, opSub, opMult(scalar), opMult(vector), opMult(matrix)**, Invert, Inverted, Orthogonalize, Orthogonalized, Reorthogonalize***, Reorthogonalized***, Det, Transpose, Transposed, Dagger*, Daggered*, Eigenvalues****, Eigenvectors****

What is the representation of matrices?

F[n*n] mat; where F is the type of the field and n is the dimension of the matrix.*The hermitian conjugate/conjugate transpose. Reduces to the transpose for a real matrix

Transposition should also be handled in a static manner, e.g. define a transposed view of a matrix that doesn't actually move elements.

Do you mean that a bool should be stored to count the number of transpositions or that there is a type that behaves like a matrix but actually just presents a view of another matrix e.g. Matrix A; ... Matrix B = A.Transposed(); //Changes to B now affect A** Matrix-matrix multiplication doesn't commute. Could this be a problem when using operator notation?

Should be fine.*** Othogonalize assuming the matrix is nearly orthogonal already (possibly using some quick, approximate method such as a Taylor series) **** I have a eigenvalue/vector solver for 3x3 matrices which seems reasonably stable but needs more testing. Free functions: MatrixToQuaternion QuaternionToMatrix + code to allow easy printing to stdout/streams and such.

Sounds encouraging. I think a good next step is to go through a community scrutiny process by dropping the code somewhere on the Web so people can review it.

would have never thought of that funky swizzling idea. I've also got another question: should matrices, vectors and quaternions be classes or structs? My gut reaction is that they should be structs and thus act like value types. But matrices might be too big and should be passed by reference which would imply they should be a class. Anyone know any rules of thumb that might apply? Gareth Charnock

Apr 18 2010

Gareth Charnock Wrote:Andrei Alexandrescu wrote:On 04/16/2010 04:25 PM, Gareth Charnock wrote:Okay, here goes. I've collected together the basic functionality that would probably make a good starting point. As I've mentioned my code is very messy and has bits missing (e.g. I never had a use for the cross product but it's pretty important in general). I guess a good way to begin would be to write the pubic interfaces then start on the implementation. Cubic Solvers: General complex cubic solver with two algorithms (one requiring a complex cosine and and arcosine one using only +-*/ and roots). A special case cubic solver for the reduced cubic x^^3 + px - q = 0.

This sounds a candidate for std.numeric. How popular/needed are cubic solvers?

They're probably don't come up that frequently but they do they're rather fiddly. Lots of operations to get right. But the solution doesn't depend on anything but basic math operators so once it's written, it's written. I guess the question is whether Phobos is meant to be a small library or a kitchen sink library.Quaternions: opAdd, opSub, opMult(quaternion), opMult(vector), opDiv, Normalise, Normalized, conjugate, conjugated, toEulerAngles*, fromEulerAngles, this(real,i,j,k), this(angle,axis), getAngle(), getAxis()

Sounds good, but you'd need to convert the code to the new overloaded operators approach.

Fair enough, and this will be a good opportunity to show off why the new overloading scheme is more powerful (e.g. opAdd and opSub can be combined).*Currently I've only got a quaternion->euler angles routine that works in the ZYZ convention but I have read a paper that generalises my method to all valid axis conventions. Will probably impliment as something like: toEulerAngles(string convention="XYZ")() Vectors: opAdd, opSub, opMult(scalar), opMult(vector)*, cross**, Normalise, Normalized, Length

What is the representation of vectors? I'm afraid the design above would be too limited for what we need.

vector is defined over is templated. What other operators are needed? I'd defiantly want to add swizzling. http://www.ogre3d.org/docs/api/html/classOgre_1_1Vector3.html looks like it could be a good source of ideas.* dot product. Would this be better named as dot()?

We already have dot product and normalization routines that work with general ranges. http://www.digitalmars.com/d/2.0/phobos/std_numeric.html#dotProduct http://www.digitalmars.com/d/2.0/phobos/std_numeric.html#normalize Generally I'd strongly suggest making operations free generic functions instead of members.

I've not really thought about operators as members vs operators as free functions. I just tend to put them as members because it feels more organised. But looking at other implementations, I seem to be in the minority.** 3D vectors only. Perhaps defining a cross product on the Matrices: opAdd, opSub, opMult(scalar), opMult(vector), opMult(matrix)**, Invert, Inverted, Orthogonalize, Orthogonalized, Reorthogonalize***, Reorthogonalized***, Det, Transpose, Transposed, Dagger*, Daggered*, Eigenvalues****, Eigenvectors****

What is the representation of matrices?

F[n*n] mat; where F is the type of the field and n is the dimension of the matrix.*The hermitian conjugate/conjugate transpose. Reduces to the transpose for a real matrix

Transposition should also be handled in a static manner, e.g. define a transposed view of a matrix that doesn't actually move elements.

Do you mean that a bool should be stored to count the number of transpositions or that there is a type that behaves like a matrix but actually just presents a view of another matrix e.g. Matrix A; ... Matrix B = A.Transposed(); //Changes to B now affect A** Matrix-matrix multiplication doesn't commute. Could this be a problem when using operator notation?

Should be fine.*** Othogonalize assuming the matrix is nearly orthogonal already (possibly using some quick, approximate method such as a Taylor series) **** I have a eigenvalue/vector solver for 3x3 matrices which seems reasonably stable but needs more testing. Free functions: MatrixToQuaternion QuaternionToMatrix + code to allow easy printing to stdout/streams and such.

Sounds encouraging. I think a good next step is to go through a community scrutiny process by dropping the code somewhere on the Web so people can review it.

would have never thought of that funky swizzling idea. I've also got another question: should matrices, vectors and quaternions be classes or structs? My gut reaction is that they should be structs and thus act like value types. But matrices might be too big and should be passed by reference which would imply they should be a class. Anyone know any rules of thumb that might apply?

I definately think low-dimensional vectors/matrices must be structs. The cost of writing/reading some float/double/real values sitting next in memory is nowhere near the cost of allocating such a new area for each opAdd. Structs can be pooled too, and referred by pointers.

Apr 19 2010

Philippe Sigaud wrote:On Mon, Apr 19, 2010 at 01:11, Gareth Charnock <gareth.tpc gmail.com <mailto:gareth.tpc gmail.com>> wrote: Couldn't agree more because I'm sure I'll miss tricks and conventions. I would have never thought of that funky swizzling idea. Here is a first try with the new operator syntax: http://lists.puremagic.com/pipermail/digitalmars-d/2010-April/074864.html Maybe it can help you...

Yeah, opDispatch is really cool. :) Here's an even earlier suggestion by Don, using inline assembler: http://www.digitalmars.com/d/archives/digitalmars/D/Re_dynamic_classes_and_duck_typing_102407.html#N102410 (Note: "opDynamic" was an early proposal. It should be replaced with "opDispatch", which is what we have now.) -Lars

Apr 19 2010

Gareth Charnock wrote:Andrei Alexandrescu wrote:On 04/16/2010 04:25 PM, Gareth Charnock wrote:

This sounds a candidate for std.numeric. How popular/needed are cubic solvers?

They're probably don't come up that frequently but they do they're rather fiddly. Lots of operations to get right. But the solution doesn't depend on anything but basic math operators so once it's written, it's written. I guess the question is whether Phobos is meant to be a small library or a kitchen sink library.

Sounds good, but you'd need to convert the code to the new overloaded operators approach.

Fair enough, and this will be a good opportunity to show off why the new overloading scheme is more powerful (e.g. opAdd and opSub can be combined).

What is the representation of vectors? I'm afraid the design above would be too limited for what we need.

vector is defined over is templated. What other operators are needed? I'd defiantly want to add swizzling. http://www.ogre3d.org/docs/api/html/classOgre_1_1Vector3.html looks like it could be a good source of ideas.* dot product. Would this be better named as dot()?

We already have dot product and normalization routines that work with general ranges. http://www.digitalmars.com/d/2.0/phobos/std_numeric.html#dotProduct http://www.digitalmars.com/d/2.0/phobos/std_numeric.html#normalize Generally I'd strongly suggest making operations free generic functions instead of members.

I've not really thought about operators as members vs operators as free functions. I just tend to put them as members because it feels more organised. But looking at other implementations, I seem to be in the minority.

What is the representation of matrices?

F[n*n] mat; where F is the type of the field and n is the dimension of the matrix.*The hermitian conjugate/conjugate transpose. Reduces to the transpose for a real matrix

Transposition should also be handled in a static manner, e.g. define a transposed view of a matrix that doesn't actually move elements.

Do you mean that a bool should be stored to count the number of transpositions or that there is a type that behaves like a matrix but actually just presents a view of another matrix e.g. Matrix A; ... Matrix B = A.Transposed(); //Changes to B now affect A

Should be fine.

Sounds encouraging. I think a good next step is to go through a community scrutiny process by dropping the code somewhere on the Web so people can review it.

would have never thought of that funky swizzling idea. I've also got another question: should matrices, vectors and quaternions be classes or structs? My gut reaction is that they should be structs and thus act like value types. But matrices might be too big and should be passed by reference which would imply they should be a class. Anyone know any rules of thumb that might apply?

IMO, general vectors/matrices should be structs wrapping a pointer to the data: struct Vector(T) { T* ptr; size_t length; size_t stride; } Low-dimensional fixed-size vectors should probably be value types. -Lars

Apr 19 2010

On 4/19/2010 6:43 AM, Lars T. Kyllingstad wrote:IMO, general vectors/matrices should be structs wrapping a pointer to the data: struct Vector(T) { T* ptr; size_t length; size_t stride; } Low-dimensional fixed-size vectors should probably be value types.

I think it would be confusing to have some vectors as value and others as reference types, unless they were different types in the library itself. I've always used two template parameters, one for type and another for size, but almost all my vectors are only 2-4 components. struct Vector(T, S) { T[S] values; } You can union things out from there so you can still have your .x/y/z properties without the overhead of a function call.

Apr 19 2010

Eric Poggel wrote:On 4/19/2010 6:43 AM, Lars T. Kyllingstad wrote:IMO, general vectors/matrices should be structs wrapping a pointer to the data: struct Vector(T) { T* ptr; size_t length; size_t stride; } Low-dimensional fixed-size vectors should probably be value types.

I think it would be confusing to have some vectors as value and others as reference types, unless they were different types in the library itself.

That was the idea, to have *both* a generic Vector(T) type and specialised Vector2D(T) and Vector3D(T) types. -Lars

Apr 19 2010

On 4/16/2010 10:41 PM, Andrei Alexandrescu wrote:Generally I'd strongly suggest making operations free generic functions instead of members.

I disagree on this one. It unnecessarily adds more names to an outer namespace and makes code less readable: vec1.cross(vec2).project(vec3).length(); vs: length(project(cross(vec1, vec2), vec3); The first reads naturally while the second is more like polish notation and is easier to forget parentheses, as I did.

Apr 19 2010

Also, the first syntax will give you intellisense in many IDE's.

Apr 19 2010

On 04/19/2010 02:41 PM, Eric Poggel wrote:On 4/16/2010 10:41 PM, Andrei Alexandrescu wrote:Generally I'd strongly suggest making operations free generic functions instead of members.

I disagree on this one. It unnecessarily adds more names to an outer namespace and makes code less readable: vec1.cross(vec2).project(vec3).length(); vs: length(project(cross(vec1, vec2), vec3); The first reads naturally while the second is more like polish notation and is easier to forget parentheses, as I did.

Notationally I agree - but you are (or at least should be) able to invoke a nonmember as if it were a member. Andrei

Apr 19 2010

Eric Poggel Wrote:On 4/16/2010 10:41 PM, Andrei Alexandrescu wrote:Generally I'd strongly suggest making operations free generic functions instead of members.

I disagree on this one. It unnecessarily adds more names to an outer namespace and makes code less readable: vec1.cross(vec2).project(vec3).length(); vs: length(project(cross(vec1, vec2), vec3); The first reads naturally while the second is more like polish notation and is easier to forget parentheses, as I did.

For the record: at least for cross(), I prefer the latter version. It always seemed awkward to me to make a symmetric (ok, anti-symmetric in this case) operation like this a member, because vec1.cross(vec2) doesn't look symmetric at all anymore. Furthermore, in the absence of an actual operator for the cross product (which we can't have, unless we resort to overloading abuse), the latter is closer to mathematical notation. -- Clemens

Apr 20 2010

For the record: at least for cross(), I prefer the latter version. It always seemed awkward to me to make a symmetric (ok, anti-symmetric in this case) operation like this a member, because vec1.cross(vec2) doesn't look symmetric at all anymore. Furthermore, in the absence of an actual operator for the cross product (which we can't have, unless we resort to overloading abuse), the latter is closer to mathematical notation. -- Clemens

I also prefer the second version. Don't we like to write max(a, b) and not a.max(b) ? Ideally I'd like to be able to write operation(x) or operation(x, y) indifferently with x and y being a scalar or a small vector type, like in shader languages. I tried with min/max but failed due to ambiguous overloading: T min(T)(T a, T b) vs vec2!(T) min(T)(vec2!(T) a, vec2!(T) b) and finally changed names (min, min2, min3...) to overcome this. D has modules, overload sets, specialization etc... so maybe someone more skilled can figure how to sort it out.

Apr 20 2010

Clemens wrote:Eric Poggel Wrote:On 4/16/2010 10:41 PM, Andrei Alexandrescu wrote:Generally I'd strongly suggest making operations free generic functions instead of members.

namespace and makes code less readable: vec1.cross(vec2).project(vec3).length(); vs: length(project(cross(vec1, vec2), vec3); The first reads naturally while the second is more like polish notation and is easier to forget parentheses, as I did.

For the record: at least for cross(), I prefer the latter version. It always seemed awkward to me to make a symmetric (ok, anti-symmetric in this case) operation like this a member, because vec1.cross(vec2) doesn't look symmetric at all anymore. Furthermore, in the absence of an actual operator for the cross product (which we can't have, unless we resort to overloading abuse), the latter is closer to mathematical notation. -- Clemens

Oddly I tend to like v1.cross(v2) because for me that feels closer to the the mathematical notation with the cross sitting between the two vectors. But for D at least it's a none issue because both will work.

Apr 20 2010

Gareth Charnock <gareth.tpc gmail.com> wrote:

Vectors: opAdd, opSub, opMult(scalar), opMult(vector)*, cross**, Normalise, Normalized, Length

Normalise and normalized seem to be inconsistent in their naming. Please use only z or only s.* dot product. Would this be better named as dot()?

Yes please.** 3D vectors only. Perhaps defining a cross product on the

Cross products are useful. Please add.Matrices: opAdd, opSub, opMult(scalar), opMult(vector), opMult(matrix)**, Invert, Inverted, Orthogonalize, Orthogonalized, Reorthogonalize***, Reorthogonalized***, Det, Transpose, Transposed, Dagger*, Daggered*, Eigenvalues****, Eigenvectors**** *The hermitian conjugate/conjugate transpose. Reduces to the transpose for a real matrix ** Matrix-matrix multiplication doesn't commute. Could this be a problem when using operator notation?

There should be no associated problems. -- Simen

Apr 16 2010

Gareth Charnock <gareth.tpc gmail.com> wrote:Vectors: opAdd, opSub, opMult(scalar), opMult(vector)*, cross**, Normalise, Normalized, Length

Oh, and perhaps add swizzling? Probably using opDispatch. -- Simen

Apr 16 2010

--0016e6dbded89d881e0484905e4d Content-Type: text/plain; charset=ISO-8859-1 On Mon, Apr 19, 2010 at 01:11, Gareth Charnock <gareth.tpc gmail.com> wrote:Couldn't agree more because I'm sure I'll miss tricks and conventions. I would have never thought of that funky swizzling idea.

Here is a first try with the new operator syntax: http://lists.puremagic.com/pipermail/digitalmars-d/2010-April/074864.html Maybe it can help you... Cheers, Philippe --0016e6dbded89d881e0484905e4d Content-Type: text/html; charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable <br><br><div class=3D"gmail_quote">On Mon, Apr 19, 2010 at 01:11, Gareth Ch= arnock <span dir=3D"ltr"><<a href=3D"mailto:gareth.tpc gmail.com">gareth= .tpc gmail.com</a>></span> wrote:<br><blockquote class=3D"gmail_quote" s= tyle=3D"margin: 0pt 0pt 0pt 0.8ex; border-left: 1px solid rgb(204, 204, 204= ); padding-left: 1ex;"> Couldn't agree more because I'm sure I'll miss tricks and conve= ntions. I would have never thought of that funky swizzling idea.<br></block= quote><div><br>Here is a first try with the new operator syntax:<br><br> <a href=3D"http://lists.puremagic.com/pipermail/digitalmars-d/2010-April/07= 4864.html">http://lists.puremagic.com/pipermail/digitalmars-d/2010-April/07= 4864.html</a><br><br>Maybe it can help you...<br><br>Cheers,<br><br><br>=A0= Philippe<br> =A0<br></div></div> --0016e6dbded89d881e0484905e4d--

Apr 18 2010

On 19-apr-10, at 01:11, Gareth Charnock wrote:Andrei Alexandrescu wrote:On 04/16/2010 04:25 PM, Gareth Charnock wrote:Okay, here goes. I've collected together the basic functionality that Quaternions: opAdd, opSub, opMult(quaternion), opMult(vector), opDiv, Normalise, Normalized, conjugate, conjugated, toEulerAngles*, fromEulerAngles, this(real,i,j,k), this(angle,axis), getAngle(), getAxis()

overloaded operators approach.

Fair enough, and this will be a good opportunity to show off why the new overloading scheme is more powerful (e.g. opAdd and opSub can be combined).

About the overloading of opIndex still think that having just an opIndexLhs might have been a little bit cleaner (you basically pick up all overloading of the underlying type without any extra code), but as overloading has become extremely easy it is not a big issue.

Apr 19 2010

Like so many hopeful enthusiasts you are trying to bring in something. I regret that I have to tell you that Phobos is a one man show. ATM we have a situation where the compiler tries to support ideas written in book not yet available for a library which exist in outer space. See concurrence (news group) ,container (D) I think we can say that Phobos is a ridiculous tiny library. but in case that you have a look on what is happening outside .. a lot. This is where your library will/can survive. Bjoern. 10000 A (B)en(H)inckle On 15/04/2010 20:49, Gareth Charnock wrote:

Apr 15 2010

BLS wrote:Like so many hopeful enthusiasts you are trying to bring in something. I regret that I have to tell you that Phobos is a one man show.

Actually, it is more like a six- or seven-man show, and the number of developers is growing.ATM we have a situation where the compiler tries to support ideas written in book not yet available for a library which exist in outer space. See concurrence (news group) ,container (D)

The concurrency stuff seems to be well under way. (An incomplete version of) std.concurrency was included with 2.043.I think we can say that Phobos is a ridiculous tiny library. but in case that you have a look on what is happening outside .. a lot. This is where your library will/can survive.

By posting messages like this, you're not exactly helping Phobos grow and gain more developers. Potential contributor: "Hey, I have some code which I think would be useful for Phobos." You: "Forget it, you'll never get it in. Besides, Phobos sucks anyway, and there's no point in trying to improve it." I mean, what are you trying to achieve with this? -LarsOn 15/04/2010 20:49, Gareth Charnock wrote:

Apr 16 2010

"Hopeful enthusiast" probably describes me quite well! :) From my point of view I can see a wheel that keeps getting reinvented (and the process of reinventing that wheel is both fiddly and quite dull), a really great looking language that needs better library support. Now I am aware that D has a reputation for not being as open as one might like, but the general consensus seems to be that things are getting better, which is why I'm posting first to check if the authors of Phobos are open to the idea of having matrices, vectors and quaternions and such. Gareth Charnock Lars T. Kyllingstad wrote:BLS wrote:Like so many hopeful enthusiasts you are trying to bring in something. I regret that I have to tell you that Phobos is a one man show.

Actually, it is more like a six- or seven-man show, and the number of developers is growing.ATM we have a situation where the compiler tries to support ideas written in book not yet available for a library which exist in outer space. See concurrence (news group) ,container (D)

The concurrency stuff seems to be well under way. (An incomplete version of) std.concurrency was included with 2.043.I think we can say that Phobos is a ridiculous tiny library. but in case that you have a look on what is happening outside .. a lot. This is where your library will/can survive.

By posting messages like this, you're not exactly helping Phobos grow and gain more developers. Potential contributor: "Hey, I have some code which I think would be useful for Phobos." You: "Forget it, you'll never get it in. Besides, Phobos sucks anyway, and there's no point in trying to improve it." I mean, what are you trying to achieve with this? -LarsOn 15/04/2010 20:49, Gareth Charnock wrote:

Apr 16 2010

On Thu, 15 Apr 2010 15:49:41 -0300, Gareth Charnock <gareth.charnock gmail.com> wrote:

I've also re-invented this wheel for my research (vectors and quaternions). I'll gladly send you a copy if you want to have a look-see.

Apr 15 2010

On 16-apr-10, at 04:46, Robert Jacques wrote:On Thu, 15 Apr 2010 15:49:41 -0300, Gareth Charnock <gareth.charnock gmail.comwrote:

I've also re-invented this wheel for my research (vectors and quaternions). I'll gladly send you a copy if you want to have a look- see.

I use (sligltly patched) omg versions of these http://team0xf.com:8080/omg that seem to work reasonably well for my purposes (D1.0) Fawzi

Apr 16 2010

On Fri, 16 Apr 2010 08:53:28 -0300, Fawzi Mohamed <fawzi gmx.ch> wrote:On 16-apr-10, at 04:46, Robert Jacques wrote:On Thu, 15 Apr 2010 15:49:41 -0300, Gareth Charnock <gareth.charnock gmail.com> wrote:

I've also re-invented this wheel for my research (vectors and quaternions). I'll gladly send you a copy if you want to have a look- see.

I use (sligltly patched) omg versions of these http://team0xf.com:8080/omg that seem to work reasonably well for my purposes (D1.0) Fawzi

However, license on these and their dependencies are not Phobos compatible.

Apr 16 2010