## digitalmars.D.learn - std.math module

- greatsam4sure (6/6) Aug 06 import std.math;
- sarn (10/16) Aug 06 That's just floating point maths for you. You're not putting
- Nicholas Wilson (3/9) Aug 06 in addition to what sarn said, tan(3pi/4) is a pole, not
- greatsam4sure (3/14) Aug 07 Thanks for the help. I will appreciate any resources for further

import std.math; import std.stdio; cos(90*PI/180) = -2.7e-20 instead of zero. I will appreciate any help. thanks in advance. tan(90*PI/180) = -3.689e+19 instead of infinity. What is the best way to use this module

Aug 06

On Sunday, 6 August 2017 at 23:33:26 UTC, greatsam4sure wrote:import std.math; import std.stdio; cos(90*PI/180) = -2.7e-20 instead of zero. I will appreciate any help. thanks in advance. tan(90*PI/180) = -3.689e+19 instead of infinity. What is the best way to use this moduleThat's just floating point maths for you. You're not putting exactly pi/2 into cos, just a good floating point approximation. What you're getting out isn't exactly 0, either, just a good floating point approximation. (-2.7e-20 is really, really small.) Here's a good talk from DConf 2016: https://www.youtube.com/watch?v=97bxjeP3LzY If you need exact maths, you'll need a symbolic manipulation library (never used one in D, but there was a discussion recently https://forum.dlang.org/thread/ghihookwgzxculshibyc forum.dlang.org). You don't need this for most practical applications, though.

Aug 06

On Sunday, 6 August 2017 at 23:33:26 UTC, greatsam4sure wrote:import std.math; import std.stdio; cos(90*PI/180) = -2.7e-20 instead of zero. I will appreciate any help. thanks in advance. tan(90*PI/180) = -3.689e+19 instead of infinity. What is the best way to use this modulein addition to what sarn said, tan(3pi/4) is a pole, not infinity. the mean of the left and right hand limits is 0

Aug 06

On Monday, 7 August 2017 at 04:47:56 UTC, Nicholas Wilson wrote:On Sunday, 6 August 2017 at 23:33:26 UTC, greatsam4sure wrote:Thanks for the help. I will appreciate any resources for further reading

Aug 07