octave

I am porting some matlab code to python using scipy and got stuck with the following line: Matlab/Octave code [Pxx, f] = periodogram(x, [], 512, 5) Python code f, Pxx = signal.periodogram(x, 5, nfft=512) The problem is that I get different output on the same data. More specifically, Pxx vectors are different. I tried different windows for signal.periodogram, yet no luck (and it seems that default scypy's boxcar window is the same as default matlab's rectangular window) Another strange behavior is that in python, first element of Pxx is always 0, no matter what data input is. Am i missing

Is it possible to make GNU Octave to output matrix dimensions together with its content? For example, it should produce smth. like this: octave:1> X = [1 2; 3 4] X [2x2] = 1 2 3 4 octave:2> X(1,:) ans [1x2] = 1 2 In MATLAB, create display.m in a folder called @double somewhere in your path with this content: function display(v) name = inputname(1); if isempty(name) name = 'ans'; end s = num2cell(size(v)); fprintf('\n%s [%d%s] =\n\n', name, s{1}, sprintf('x%d', s{2:end})); builtin('disp', v); end This way you override the display method for class double , and get exactly what you have described

Matlab/Octave algorithm example: input vector: [ 1 0 2 0 7 7 7 0 5 0 0 0 9 ] output vector: [ 1 1 2 2 7 7 7 7 5 5 5 5 9 ] The algorithm is very simple: it goes through the vector and replaces all zeros with the last non-zero value. It seems trivial, and is so when done with a slow for (i=1:length) loop and being able to refer to the previous element (i-1), but looks impossible to be formulated in the fast vectorized form. I tried the merge() and shift() but it only works for the first occurrence of zero, not an arbitrary number of them. Can it be done in a vectorized form in Octave/Matlab or

I have the file data.txt with two columns and N rows, something like this: 0.009943796 0.4667975 0.009795735 0.46777886 0.009623984 0.46897832 0.009564759 0.46941447 0.009546991 0.4703958 0.009428543 0.47224948 0.009375241 0.47475737 0.009298249 0.4767201 [...] Every couple of values in the file correspond to one point coordinates (x,y). If plotted, this points generate a curve. I would like to calculate the area under curve (AUC) of this curve. So I load the data: data = load("data.txt"); X = data(:,1); Y = data(:,2); So, X contains all the x coordinates of the points, and Y all the y

Octave appears to assume that a specific sound playing utility will be available on a system but doesn't seem to provide the ability to specify an alternate. In the error below, Octave is looking for ofsndplay , which is not a utility available on all systems. octave:38> sound(beamformed_20) sh: ofsndplay: command not found Is there an Octave configuration setting or code fragment that I can use to specify an system-appropriate utility? I've overridden the playaudio function from octave with the following function. This will work only after installing sox . sudo apt-get install sox (in ubuntu)

I have a function that tells me the nth number in a Fibonacci sequence. The problem is it becomes very slow when trying to find larger numbers in the Fibonacci sequence does anyone know how I can fix this? function f = rtfib(n) if (n==1) f= 1; elseif (n == 2) f = 2; else f =rtfib(n-1) + rtfib(n-2); end The Results, tic; rtfib(20), toc ans = 10946 Elapsed time is 0.134947 seconds. tic; rtfib(30), toc ans = 1346269 Elapsed time is 16.6724 seconds. I can't even get a value after 5 mins doing rtfib(100) PS: I'm using octave 3.8.1 If time is important (not programming techniques): function f = fib