IQmath - log function

Excellent!!! will put this in use very soon .... again, many thanks for this level of support.

Hi Lori

Would you please update the schedule for an official release of this library?

Hi Lori,

I try to use the IQlog function bud I get the following error.

<Linking>

undefined                        first referenced
 symbol                              in file
---------                        ----------------
_IQlogTableCoeff                 ...\\IQmathLog.lib
>>   error: symbol referencing errors

Any idea how I can solve this?

Thanks

Hans

Hans Vandenbussche said:

Hi Lori,

I try to use the IQlog function bud I get the following error.

<Linking>

undefined                        first referenced
 symbol                              in file
---------                        ----------------
_IQlogTableCoeff                 ...\\IQmathLog.lib
>>   error: symbol referencing errors

Any idea how I can solve this?

Thanks

Hans

 

Hans,

I tried to reproduce the error without luck.   The error indicates the table is not found, but it is included in the library.   Are you still having the issue?

As a side note, this function was integrated into the latest IQmath release:  V15c which is available in controlSUITE (www.ti.com/controlSUITE).

More on controlSUITE here: http://processors.wiki.ti.com/index.php/ControlSUITE_for_C2000

-Lori

 EDIT: log function is not integrated into the 1.5c release

Hi Lori, thanks for your answer. I installed the controlSUITE and currently I'm using the IQmath V15c. Seems there is no IQlog function integrated. I don't find anything back in the (new) header file?! I'm still having this issue, any help would be appreciated.

Thanks

Hans

Hans Vandenbussche said:

Hi Lori, thanks for your answer. I installed the controlSUITE and currently I'm using the IQmath V15c. Seems there is no IQlog function integrated. I don't find anything back in the (new) header file?! I'm still having this issue, any help would be appreciated.

Thanks

Hans

 

Hans,

I am embarrassed - I misspoke.  The IQlog is not integrated into the v1.5c release.  My apologies.   Unfortunatly I am not able to reproduce the problem with the IQ log function attached to this thread.   I will try a few more things today to see if I can reproduce it.

-Lori

Hans,

Which version of the code generation tools are you using?  It will be something like 5.2....  You can find it on the top of any generated .map file.

-Lori

Hans,

I was able to reproduce the issue using codegen 4.x.  It doesn't seem to happen with newer codegen tools. 

I've attached a fix to the library that will allow it to work with the older codegen.  Please let me know how it goes.

-Lori

Lori,

Thank you very much for your efforts, this works fine.

Regards,

Hans

Dear Lori,

I am very excited to see that there is log() support now in IQMath.  I tried installing it onto my system using Code Composer 4.1.2.00027.

I put it in the IQMath folder, then add the path in the includes section in the Compiler section and  the IQmathLog.lib File Search Path in the C2000 Linker section.

I implemented the code to your example (see below) but get a linker error:

"unresolved symbol _IQ24log(long), first referenced in ./FrontPanel.obj"

Do you have any ideas why this would happen?

Thanks - Cyril

-----------------------------------------

#include "IQmathLib.h"
#include "IQlog.h"

...

main()
{
    _iq x;
    _iq y;
    
....
   y = _IQ(1.5); 
   x = _IQlog(y);  // x =  0.405465108
  
  
}

Just a follow-on...

I did try explictily Linking the file IQMathLog.lib to the project in the Projects window....

Code Generation tools:  TMS320C2000 Linker PC v5.2.3

Line in MAP file when I get this error: 

UNDEFED __IQ24log__Fl

003ff3c2 __IQ24sin

003f6f77 __IQ24toF

Not sure if this helps at all....

Thanks!

Cyril

One more curiousity... this is a C++ project.  Could that be causing the issues?

Hello,

This issue has been resolved.  The code example was updated to use

extern "C"

{

#include IQlog.h

}

Please refer to the updated readme.txt. 

August 3rd, 2010

Preliminary IQmath Natural log function.

Two libraries are included:

(a) IQmathLog.lib: This build of the library can be linked with code built for fixed-point.
(b) IQmathLog_f32.lib: This build of the library can be linked with code built with the --float_support=fpu32 switch. 
    This can be useful for mixing IQmath with native floating-point code on devices with the C28x+FPU.

This library includes only the natural log function: 

_iq   _IQlog( _iq A)      ; Q = GLOBAL_Q

_iqN  _IQNlog( _iqN A)    ; Q = 1-29


Cycles: ~148 (includes call & return)
This function does not use a lookup table.


Example:

#include "IQmathLib.h"
#include "IQlog.h"

...

main()
{
    _iq x;
    _iq y;
    
    
....
   y = _IQ(1.5);  
   x = _IQlog(y);  // x =  0.405465108
   
   
}


Example C++:
#include <stdio.h>
#include <stdlib.h>

extern "C" {
#include "IQmathLib.h"
}

extern "C" {
#include "IQlog.h"
}

#include "IQmathCPP.h"

inline iq24 IQ24log(const iq24 & x)
{
	iq24 temp;
	temp.val = _IQ24log(x.val);
	return temp;	
}


int main(void)
{
	
   iq24 	one, two;
	
    two = IQ24log(1.5);  
    one = IQ24log(two);  
    
}

Hey All,

IQlog works great once I remembered the C++ issue!  Thanks for the support Devin.

Now, what's the chances of an IQpow(n,x) function?  I use a lot of equations with 2**x...

Is there any tricky way to do that right now using IQMath?

(I am using a F28033 on this project.... using that standard math.h function - it takes 75 usec!)

Thanks again,

Cyril

Hi Lance,

I'm now using IQmath for C64x+. Can you or somebody else who is interested in IQmath, run the following code

1) set GLOBAL_Q (18)

2) run

    temp=_IQlog(_FtoIQ(0.025));

Here temp is a _iq number.

Theoretically temp should be negative number, but I got a positive number which is wrong. Thanks, David.