ch4_1a.mw


Session 4.1 Maple programs Part a defining expressions and programs in a session

> restart;   A new session

> f1:=sin(z);   One expression

f1 := sin(z)

> f2:=z^2-1;    Another expression

f2 := z^2-1

> z:=3.0; f1; f2;

z := 3.0

.1411200081

8.00

Now we will type in a procedure called trigl

> trigl:=proc(n,x0,dx)              Define procedure and parameters
local x,k;
                                                     Identify local variables
for k from 1 to n do
                              Create loop from 1 to n w/ k as counter
   x:=x0+(k-1)*dx;
   lprint(x,sin(x),cos(x))
od;
end;
                                                                  Hit Return to define program

trigl := proc (n, x0, dx) local x, k; for k to n do x := x0+(k-1)*dx; lprint(x, sin(x), cos(x)) end do end proc

The program is defined as listed above.  Note the punctuation in the program.

There is a semicolon after the definition of x, at the end of the do loop,

and at the end of the program.  

Here is an example of the program being called:

> trigl(5,0,0.5);It's not pretty, but it gives five values for sin and cos with the argument starting at 0 and continuing in steps of 0.5.

0., 0., 1.
.5, .4794255386, .8775825619
1.0, .8414709848, .5403023059
1.5, .9974949866, 0.7073720167e-1
2.0, .9092974268, -.4161468365