I have a code in the format of visual basic. I want to convert it to Matlab. My goal is to understand the content and formulation which is used in visual basic code. but I didn't experienced V.B so far.
thanks dear Aparna. hit-or-miss the logic is about FFt (fast fourier transform) which is used for a structural dynamics problem and also you may dealing it for signal processing in Electrical Engineering.
I prefer to use 'fft' build-in function in Matlab for solving the following problem (see Fig.1). the formulation is shown in Fig. 2. In my matlab code Force Fourier Coeff. and half of Response Fourier Coeff. are calculated successfully (Fig. 3) but Disp.Real and Disp.Imag are not matched with results of the example (Fig. 4). Where do I mistake??
Yes. Really, it is complex. but the formulation enforce us to use FFC in calculation of RFC. Of course the FFC can be corrected manually (because of symmetry around N/2+1=9). but the main problem are Disp.Real and Disp.Imag.
Recently I fix it by adding a loop that create symmetric values about point N/2+1=9 for calculating RFC. Then displacements calculated successfully by using "Disp=ifft(RFC)*16".
but I can not realize why RFC which is obtained from Matlab function (fft) is not symmetric?