Re: [Tinyos-help] Logarithmic function
Firstly, excuse me for insisting so much on this, but I really do not know what to do. I use telosb motes and an external sensor and I need to use the natural logarithmic function in order to convert the adc value of the sensor. I tried: #include math.h ... x=log(y); but at make I get: app.c:(.text+0x18a6): undefined reference to `log' make: *** [exe0] Error 1 I also tried: #include math.h ... x=logf(y) as a friend from this mail list suggested (thanks!) and then the compilation was okay but the results of logf were wrong! It does not compute ln or log. I also tried: #include math.h ... x=log(y); and at Makefile: CFLAGS += -l$/usr/msp430/include but then I got: msp430-ld: cannot find -lusr/msp430/include make: *** [exe0] Error 1 What should I do to use math.h? Also, in all math.h files I could find there is not such a function as logf()! So, why is it possible to be compiled? Sorry for writing again for the same issue. Regards, Georgia ___ Tinyos-help mailing list Tinyos-help@millennium.berkeley.edu https://www.millennium.berkeley.edu/cgi-bin/mailman/listinfo/tinyos-help
Re: [Tinyos-help] Logarithmic function
Oops, my bad! Actually logf() works fine. It computes ln correctly. I still cannot find it in any of the math.h files but it works. Sorry again. ___ Tinyos-help mailing list Tinyos-help@millennium.berkeley.edu https://www.millennium.berkeley.edu/cgi-bin/mailman/listinfo/tinyos-help
Re: [Tinyos-help] Logarithmic function
I have two different versions of msp430 tools courtesy of different mystery TOS installations, one in /usr and one in /opt. They both have the same directory structure, so the only math.h file I could find was: .../msp430/msp430/include/math.h Both contain a logf() declaration, and a logf10()... To show my ignorance I remembered that log was base 10 not ln, so that probably tells you how useful my information is... MS Geo Gkolfin wrote: Oops, my bad! Actually logf() works fine. It computes ln correctly. I still cannot find it in any of the math.h files but it works. Sorry again. ___ Tinyos-help mailing list Tinyos-help@millennium.berkeley.edu https://www.millennium.berkeley.edu/cgi-bin/mailman/listinfo/tinyos-help ___ Tinyos-help mailing list Tinyos-help@millennium.berkeley.edu https://www.millennium.berkeley.edu/cgi-bin/mailman/listinfo/tinyos-help
Re: [Tinyos-help] Logarithmic function
Dear Mr Michael Schippling Thank you so much for both your help and your irony. I am afraid I was looking at avr! After your enlightening reply I was able (at last) to find logf. Unfortunately I cannot understand the base 10 ironic part of your mail. But logf(2.718) returns 1 so I guess logf computes the Neperian logarithm. Excuse me if my comment is irrelevant. Once again thank you for replying. Please keep up the good work helping us and the positive energy. Best regards, Georgia On Sun, Jul 31, 2011 at 7:37 PM, Michael Schippling sc...@santafe.eduwrote: I have two different versions of msp430 tools courtesy of different mystery TOS installations, one in /usr and one in /opt. They both have the same directory structure, so the only math.h file I could find was: .../msp430/msp430/include/**math.h Both contain a logf() declaration, and a logf10()... To show my ignorance I remembered that log was base 10 not ln, so that probably tells you how useful my information is... MS Geo Gkolfin wrote: Oops, my bad! Actually logf() works fine. It computes ln correctly. I still cannot find it in any of the math.h files but it works. Sorry again. --**--** __**_ Tinyos-help mailing list Tinyos-help@millennium.**berkeley.eduTinyos-help@millennium.berkeley.edu https://www.millennium.**berkeley.edu/cgi-bin/mailman/** listinfo/tinyos-helphttps://www.millennium.berkeley.edu/cgi-bin/mailman/listinfo/tinyos-help ___ Tinyos-help mailing list Tinyos-help@millennium.berkeley.edu https://www.millennium.berkeley.edu/cgi-bin/mailman/listinfo/tinyos-help
Re: [Tinyos-help] Logarithmic function
The base10 log ironic part was a reference to how bad my memory is of math functions that I don't often use... I also forgot that avr math.h uses doubles... hope things keep working for you MS Geo Gkolfin wrote: Dear Mr Michael Schippling Thank you so much for both your help and your irony. I am afraid I was looking at avr! After your enlightening reply I was able (at last) to find logf. Unfortunately I cannot understand the base 10 ironic part of your mail. But logf(2.718) returns 1 so I guess logf computes the Neperian logarithm. Excuse me if my comment is irrelevant. Once again thank you for replying. Please keep up the good work helping us and the positive energy. Best regards, Georgia On Sun, Jul 31, 2011 at 7:37 PM, Michael Schippling sc...@santafe.edu mailto:sc...@santafe.edu wrote: I have two different versions of msp430 tools courtesy of different mystery TOS installations, one in /usr and one in /opt. They both have the same directory structure, so the only math.h file I could find was: .../msp430/msp430/include/__math.h Both contain a logf() declaration, and a logf10()... To show my ignorance I remembered that log was base 10 not ln, so that probably tells you how useful my information is... MS Geo Gkolfin wrote: Oops, my bad! Actually logf() works fine. It computes ln correctly. I still cannot find it in any of the math.h files but it works. Sorry again. --__--__ _ Tinyos-help mailing list Tinyos-help@millennium.__berkeley.edu mailto:Tinyos-help@millennium.berkeley.edu https://www.millennium.__berkeley.edu/cgi-bin/mailman/__listinfo/tinyos-help https://www.millennium.berkeley.edu/cgi-bin/mailman/listinfo/tinyos-help ___ Tinyos-help mailing list Tinyos-help@millennium.berkeley.edu https://www.millennium.berkeley.edu/cgi-bin/mailman/listinfo/tinyos-help
[Tinyos-help] Logarithmic function?
Hello, I am using a telosb mote and I am trying to convert the adc value of an external temp sensor in Celsius. The conversion formula uses the logarithmic function. I need to compute ln(x/y). I tried log(x/y) as in C, but it is not correct. Could someone help me? Thanks in advance! ___ Tinyos-help mailing list Tinyos-help@millennium.berkeley.edu https://www.millennium.berkeley.edu/cgi-bin/mailman/listinfo/tinyos-help
Re: [Tinyos-help] Logarithmic function?
there may be a logf(float) function. Look in the relevant math.h file to see what's what. MS Geo Gkolfin wrote: Hello, I am using a telosb mote and I am trying to convert the adc value of an external temp sensor in Celsius. The conversion formula uses the logarithmic function. I need to compute ln(x/y). I tried log(x/y) as in C, but it is not correct. Could someone help me? Thanks in advance! ___ Tinyos-help mailing list Tinyos-help@millennium.berkeley.edu https://www.millennium.berkeley.edu/cgi-bin/mailman/listinfo/tinyos-help ___ Tinyos-help mailing list Tinyos-help@millennium.berkeley.edu https://www.millennium.berkeley.edu/cgi-bin/mailman/listinfo/tinyos-help
