Trigonometric functions in AMPL

[Vivi]

Hello,

I would like to know how to write trigonometric functions like cos and sin in AMPL program and how to manage their units.

Best regards,

[AMPL Google Group]

The trigonometric functions available in AMPL are listed in Table A-2 of the AMPL book. You can write cos(. . .) and sin(. . .) for the cosine and sine functions, where . . . is replaced by any AMPL numerical expression. The units of AMPL trigonometric functions are radians, as you can see in this example:

ampl: param pi = 3.141592653589793;
ampl: display sin(pi), cos(pi);
sin(pi) = 1.22465e-16
cos(pi) = -1

(The value of sin(pi) comes out slightly nonzero because pi cannot be represented exactly in computer arithmetic.) You can easily convert from degrees; here is an example of showing the sine and cosine of 90 degrees:

ampl: param c = 180/pi;
ampl: display sin(90/c), cos(90/c);
sin(90/c) = 1
cos(90/c) = 6.12323e-17

--
Robert Fourer
am...@googlegroups.com

{#HS:2044147981-112454#}

[Vivi]

Dear Mr Robert,

Many thanks for your assistance.

Best regards,