[Alon2k2]

Hi,

I have a problem with doing calculations like 0.01 + 0.03.
Is there toFixed for this thing like in JavaScript?

new Float:floatVal = 0.01 + 0.03;
PrintToChat(client, "$%.2f", floatVal); // $0.03 wrong!!

[helloworlds]

There's probably some more elegant way to do this with arithmetic and/or bit fiddling, but here's one approach that takes advantage of the "FloatToString" function handling this case automagically. It should at least solve your example case.

PHP Code:

#include <sourcemod>

// Parameters:
// f - Floating point number to convert.
// n - At how many decimal points to truncate at.
// out - Buffer to store string in.
// maxlen - Maximum length of string buffer.
// Return value: Number of characters written to the buffer, not including the null terminator.
int FloatToStringTruncate(float f, int n, char[] out, int maxlen)
{
    int res = FloatToString(FloatFraction(f), out, maxlen);
    int cutoff = 3 + n;
    if (cutoff >= maxlen)
    {
        return res;
    }
    out[cutoff] = '\0';
    return Format(out, cutoff, "%d%s%s",
        RoundToFloor(f),
        n <= 0 ? "" : ".",
        out[n <= 0 ? 3 : 2]
    );
}

public void OnPluginStart()
{
    float f = 0.04;
    PrintToServer("Plain: %f", f);

    PrintToServer("Format-class functions: %.2f", f);

    char buffer[32];
    FloatToStringTruncate(f, 2, buffer, sizeof(buffer));

    PrintToServer("FloatToStringTruncate: %s", buffer);
} 


...or whatever "truncate at n chars after the decimal point" method you'd wanna use.

This outputs:

Plain: 0.039999 Format-class functions: 0.03 FloatToStringTruncate: 0.04

[101]

Originally Posted by helloworlds There's probably some more elegant way to do this with arithmetic and/or bit fiddling, but here's one approach that takes advantage of the "FloatToString" function handling this case automagically. It should at least solve your example case. PHP Code: #include <sourcemod> // Parameters: // f - Floating point number to convert. // n - At how many decimal points to truncate at. // out - Buffer to store string in. // maxlen - Maximum length of string buffer. // Return value: Number of characters written to the buffer, not including the null terminator. int FloatToStringTruncate(float f, int n, char[] out, int maxlen) {     int res = FloatToString(FloatFraction(f), out, maxlen);     int cutoff = 3 + n;     if (cutoff >= maxlen)     {         return res;     }     out[cutoff] = '\0';     return Format(out, cutoff, "%d%s%s",         RoundToFloor(f),         n <= 0 ? "" : ".",         out[n <= 0 ? 3 : 2]     ); } public void OnPluginStart() {     float f = 0.04;     PrintToServer("Plain: %f", f);     PrintToServer("Format-class functions: %.2f", f);     char buffer[32];     FloatToStringTruncate(f, 2, buffer, sizeof(buffer));     PrintToServer("FloatToStringTruncate: %s", buffer); }  ...or whatever "truncate at n chars after the decimal point" method you'd wanna use. This outputs:

I Don't Know Why This Happens , But What about this :

PHP Code:

#include <sourcemod>
#define fix    0.0000001 // Fix ONLY FOR PRINT Floats (Don't Use During Calculations)

public OnPluginStart() 
{
    RegServerCmd("sm_test",Command_test,"Test Floats");
}

public Action:Command_test(args)
{
    float X=0.03;
    float Z=0.01;
    PrintToServer("fixed X+Z = %f",X+Z+fix); // Result 0.040000
    PrintToServer("Abs X+Z = %f",X+Z); // Result 0.039999
} 


[helloworlds]

Originally Posted by 101 I Don't Know Why This Happens [...]

It has to do with the fact that float32 are represented as a sign bit, 8 bits for exponent, and 23 bits for the fraction, and you just can't represent all values accurately with this. For more info, see:
https://en.wikipedia.org/wiki/IEEE_754, https://en.wikipedia.org/wiki/Single...g-point_format

[101]

So the bits of fraction insist on carrying Nonzero numbers no matter what the result!

by the way, thank you I found extra information here :
https://stackoverflow.com/questions/...floating-point

But who can believe that 0.039999 is closer to 0.04 than (0.040000 itself)!