CodeWarrior for MCU中的主题 Re: how to use the sin function

how to use the sin function

subbaraju — Tue, 20 Mar 2007 14:40:24 GMT

hi
i want to use the sine and cosine functions for my project implementaion. as i am new to codewarrior can any one help me in using the sin functions and printf statements i am working on m68hc12dp256 evaluation board.
i tried the following code
# include
void main(void){
int i=1; double y[10];
for(i=1;i10;i++){
y[i]=double (sin (double i));
}
}
if i try to compile it, giving errors saying error: c2450 expected .* + - etc., (expected 'double*' instead of 'double'); what it is meaning
secondly
i am not able to implement the printf statement?

thanking you in advance.

quick response is required.

regards
Subbaraju P.

Re: how to use the sin function

CompilerGuru — Tue, 20 Mar 2007 20:47:10 GMT

>y[i]=double (sin (double i));

I guess this should just be

y[i]=sin(i);

Why those extra double's?

About printf, is your problem a link time error of not finding TERMIO_PutChar?
If so, search this forum for TERMIO_PutChar.
To use printf with doubles, also make sure your STACKSIZE in the prm is big enough.

Daniel

Re: how to use the sin function

J2MEJediMaster — Tue, 20 Mar 2007 21:02:19 GMT

It's not clear from your code, but do you include math.h to define the sin/cos functions? Also, make sure that you're linking the correct library that contains both the trigonometric functions and the printf code. Check the readme.txt files that accompany the libraries in the lib directory for more information on what functions each library file contains.

---Tom

Re: how to use the sin function

subbaraju — Wed, 21 Mar 2007 15:07:54 GMT

J2MEJediMaster wrote:
It's not clear from your code, but do you include math.h to define the sin/cos functions? Also, make sure that you're linking the correct library that contains both the trigonometric functions and the printf code. Check the readme.txt files that accompany the libraries in the lib directory for more information on what functions each library file contains.

---Tom

Thanks for your help now i am able to work with sine function. but i am facing the problem of memory. for the same program if i increase the array size of y to 20 then in debugging it is indicated that no memory FFe:2 at the bottom and the debugging is not proceding. please suggest a possible solution to the problem.
thanking you.

Re: how to use the sin function

CrasyCat — Wed, 21 Mar 2007 18:11:03 GMT

Hello

According to the code snippet you sent over, y is a local variable. is that right?

The table will take a lot of space on the stack, which might overflow.

Can you try to either define a bigger stack in the .prm file or define the table as a global variable.

Is that working better?

CrasyCat