mex run time error
in [Matlab]
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From: skyworld on 8 Jul 2010 21:47 On Jul 9, 9:12 am, skyworld <chenyong20...(a)gmail.com> wrote: > On Jul 8, 11:17 pm, "Jan Simon" <matlab.THIS_Y...(a)nMINUSsimon.de> > wrote: > > > Dear Yong, > > > > double tmp_x[DATA_NUM]; > > > tmp_x[i] = 12; > > > mexPrintf("tmp_x=%d\n",tmp_x[i]); > > > Your tmp_x is a double vector. Display doubles with the format "%f" or "%g", because "%d" formats integers. > > > Please post just the relevant part of the code and omit all lines, which are not involved in the runtime error. > > > Good luck, Jan > > Hi Jan, > > thanks for your kind information. You just point out one of my errors. > Thanks. A very annoying problem is that when I revised %d to %f, there > is no messages on command window output. When I change back to %d, > also no output. totally different from yesterday. That is my life.... > > regards > yong Hi Jan, I found the reason and now I can display right data. thanks for your help. regards
From: skyworld on 8 Jul 2010 22:35
On Jul 9, 9:22 am, skyworld <chenyong20...(a)gmail.com> wrote: > On Jul 9, 2:35 am, "James Tursa" > > > > > > <aclassyguy_with_a_k_not_...(a)hotmail.com> wrote: > > skyworld<chenyong20...(a)gmail.com> wrote in message <9eb6e874-c2c3-4de1-ad17-446a3c028...(a)k8g2000prh.googlegroups.com>... > > > > I wrote a mex file like this: > > > (snip) > > > > It is very interesting that I can't get right data from x_data, > > > coef_data and tmp_x. The display shows these data are very huge > > > numbers, which I think should be within +/- 4. And sometime when I run > > > the m file, the matlab will report run-time error. Could anybody help > > > me to find what is wrong with this code? thanks. > > > You are probably exceeding valid indexes for the arrays. Impossible to tell for sure because you didn't post enough information about size of the inputs. e.g., I would suspect this line: > > > > y_data_array[i] += x_data[i+j]*coef_data[COEF_NUM-j-1]; > > > Does x_data really contain 511+6+1 = 518 elements? > > > Try putting in some checks to see that your sizes and indexing are all consistent. > > > James Tursa > > Hi James, > > thanks for your message. In fact I'm trying to write a code for FIR > check so that it could be used in HW co-simulation. My inputs to this > function are two arguments: x_data with 512 samples and coefficients > with 7 taps. In order to match matlab filter outputs, I guess I need > to pad 6 zeros before x samples. That is the reason I defined tmp_x. > My purpose would like to do this: > for (i=0 to i=5) tmp_x(i) = 0; > for (i=6 to i=518) tmp_x(i) = x_data(i-6); > then I will do fir multiply-addition as > y_data_array[i] += x_data[i+j]*coef_data[COEF_NUM-j-1]; > > I met two problems when doing above: > 1) I can't get right data in tmp_x from x_data. I use code like these > to check if tmp_x got data from x_data > for (i=0;i<DATA_NUM;i++) > { > tmp_x[i] = 12; > mexPrintf("tmp_x=%d\n",tmp_x[i]); > tmp_x[i] = x_data[i]; > mexPrintf("i=%d, x=%d, tmp_x=%d\n",i,x_data[i],tmp_x[i]); > } > the display shows two data are different. > > 2) If I use only 512 x sample to do fir calculation, the result seems > ok. But if I run this program several times, there maybe run-time > error. I don't know what kind of hidden issues in my code. > > thanks.- Hide quoted text - > > - Show quoted text - Hi James, I solved it. Thanks for your help very much. regards |