I am trying to write a quick program in C that uses sin/cos. But all the variables I use are ints (whereas sin/cos need floats). So KermM gave me some code to try for that: (int)sin((float)myinteger)

But, I think something is up because I get this error(s):

$ make
nspire-gcc -Os -Wall -W -fpic -fno-merge-constants -D NON_CAS -c main.c
main.c: In function 'main':
main.c:64:3: warning: implicit declaration of function 'cos'
main.c:64:13: warning: incompatible implicit declaration of built-in function 'cos'
main.c:65:3: warning: implicit declaration of function 'sin'
main.c:65:13: warning: incompatible implicit declaration of built-in function 'sin'
nspire-ld main.o utils.o graphics3.o -o Trapped.elf
main.o: In function `main':
main.c:(.text+0xd8): undefined reference to `cos'
main.c:(.text+0x278): undefined reference to `cos'
main.c:(.text+0x2a4): undefined reference to `sin'
main.c:(.text+0x330): undefined reference to `cos'
main.c:(.text+0x358): undefined reference to `sin'
collect2: ld returned 1 exit status
make: *** [Trapped.tns] Error 1




On this line: y += (int)sin((float)direction) * y_speed;


Any help please :)

Try adding the -lm flag in your Makefile.

Edit: apparently there's no such thing as the standard libmath functions for the Nspire. Try bwang's nmath file.

You'd usually need to #include <math.h> to use sin/cos in any case. See Kerm's answer for Nspire-specific details, though.

Aye, I was assuming that he had at least done that; maybe I shouldn't have made that assumption.

Nope, he forgot to include the header.

player1537, maybe you should start with an intro to C - you clearly have no idea how to program in C, or these errors would have been obvious in their meaning.

No, he is indeed a C newbie, but he's learning. Come on, we all had to start somewhere; even I was once baffled by pointers.