floating error

[Oktay]

Hi,
I have CCS PCM compiler ver 3.088
but floating point error

#define f1 1.41
#define f2 2.76
#define f3 3.14

printf(lcd_putc,"\%\f1.2f \%1.2f \%1.2f",f1,f2,f3);

On Display
1.40 2.75 3.14

Why?
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This message was ported from CCS's old forum
Original Post ID: 144515001

[Steve H.]

A PIC isn't a PC with unlimited resources and double precision math. You are trying to shove a decimal number into a limited precision binary representation. Without rounding errors you are lucky to get 3 digits.

For precise outputs you should consider using fixed point math with int's or long's and add the decimal point for the user display only.

This topic has been covered before on this board, search fixed point, float error, rounding, etc.
___________________________
This message was ported from CCS's old forum
Original Post ID: 144515006