float numbers

[JPL]

I have some problems with float numbers ...

problem 1:

how to declare float constant?

now I solve the problem by this way:

var float10[2]; // float variable
flt_ITOF(float10, 10 ); //Convert integer 10 to float

I would like to define a float constant with value 10.0
how to do that ?

Beside the value 10.0 I need to define a constant with a number like -5.7750E-07 and -4.1830E-12

Is it possible to have:

#CONST
floatA[2]
floatB[2] ...
#END


problem 2:

how to move float value from one float variable to other float variable?

simple example:

var floatA[2]; // float variable A
var floatB[2]; // float variable B
flt_ITOF(floatA, 5 ) ; //Convert integer 5 to floatA

how to move or copy now value from floatA to floatB ?

now I solve this problem with subtraction of zero from floatA and store result in floatB...

[JPL]

concerning problem 1, I have found in the meantime this:

https://forum.4dsystems.com.au/node/65427

but how about the problem 2?

[pauleilio]

Hi

You could use this command to copy the contents of one array to another

mem_Copy(floatA, floatB, 4);

The number 4 is the amont of bytes that you will copy so as it is a float and each array cell is 2 bytes wide, you need to copy 4 over.

I hope this helps

Best regards

Paul

[JPL]

The
https://forum.4dsystems.com.au/node/65427
solved problem how to define the float constants, but I have calculation problem.
My constants are too small

-5.7750E-07 and -4.1830E-12

If used in calculation, the constants are recognized as zero ( 0.000000000 ) and calculation error is too big. How to increase precision of constants?

[JPL]

I have tersted these two constructions:

example 1:

#DATA
byte I_A "3.9083E-03\0"
byte I_B "-5.7750E-07\0"
byte I_C "-4.1830E-12\0"

#END

var I[3]:= [I_A,I_B,I_C];

var float_A[2];
var float_B[2];
var float_C[2];

func coco()

flt_VAL(float_A, I[1]);
flt_VAL(float_B, I[2]);
flt_VAL(float_C, I[3]);

txt_Set(FONT_ID, 4);
txt_MoveCursor(5, 2);
flt_PRINT(float_B, "B: %.12f ");

endfunc

example 2:

#DATA
word I_A "3.9083E-03\0" // I constants
word I_B "-5.7750E-07\0"
word I_C "-4.1830E-12\0"

#END

var I[3]:= [I_A,I_B,I_C];

var float_A[4];
var float_B[4];
var float_C[4];

func coco()

flt_VAL(float_A, I[1]);
flt_VAL(float_B, I[2]);
flt_VAL(float_C, I[3]);

txt_Set(FONT_ID, 4);
txt_MoveCursor(5, 2);
flt_PRINT(float_B, "B: %.12f ");

endfunc

Unfortunately, both print V: 0.000000000 Can you help?

[JPL]

if changed in example (1) above

flt_VAL(float_A, I[1]);
flt_VAL(float_B, I[2]);
flt_VAL(float_C, I[3]);

txt_Set(FONT_ID, 4);
txt_MoveCursor(5, 2);
flt_PRINT(float_B, "B: %.12f ");

to

flt_VAL(float_A, I[0]);
flt_VAL(float_B, I[1]);
flt_VAL(float_C, I[2]);

txt_Set(FONT_ID, 4);
txt_MoveCursor(5, 2);
flt_PRINT(float_B, "B: %.6e ");

I am giving correct result at printing. BUT in next calculation the values of float_A , float_B, float_C appears to be still zero...

[pauleilio]

Hi

You can also do things like this,

flt_ADD(f, "1.234", "5.678");

The compiler effectively puts the constants in data, so, of course, you can do it more verbosely like this

#DATA
byte flt4 "1.2354\0"
byte flt5 "1.3e2\0"
#END
…
flt_ADD(f, flt4, flt5);

Best regards

Paul