Setting an Hourly x-Axis to plot Accumarray in Matlab
I guess you just want the x ticks to be spaced by 1 hour, independently of the data spacing? From your example, I don't see that you necessarily have a data point once an hour. If my understanding is correct, try replacing datetick('x','ddd HHPM') with the following: hr_step = 0.0417;...
expanded accumarray output for unsorted data in matlab
You basically need to replicate the output of accumarray. The replication pattern is given by the third output of unique: [~, ~, k] = unique(id); s = accumarray(k,data); result = s(k); Another possibility: use bsxfun to detect equal values of id, and then matrix multiplication to accumulate the corresponding values...
Fast rolling correlation in Matlab
Following the advice from @knedlsepp, and using filter as in the movingstd, I found the following solution, which is quite fast: function Cor = MovCorr1(Data1,Data2,k) y = zscore(Data2); n = size(y,1); if (n<k) Cor = NaN(n,1); else x = zscore(Data1); x2 = x.^2; y2 = y.^2; xy = x .*...
Count occurences of strings in column - Matlab
You can use unique with histc - %// Get countries and their occurences [countries,~,id] = unique(cellstr(val),'stable') occurrences = histc(id,1:max(id)) You can then display the number of occurrences against the country names as a table - >> table(countries,occurrences) ans = countries occurrences _________ ___________ 'USA' 3 'France' 2 Display output as...
Stable accumarray in MATLAB
We can use sortrows as a preprocessing step to sort the indices and corresponding values first, as its documentation states: SORTROWS uses a stable version of quicksort. As the subscripts in subs should be sorted with respect to their linear indices, we need to sort them in reverse lexicographic order....
Matlab - Accumarray confusion?
As described in the docs for accumarray: Considering a call to the function like the following: A = accumarray(subs,val) The values in each row of the m-by-n matrix subs define an n-dimensional subscript into the output, A. Therefore, in your case since subs is a Something x 2 array, each...
Using percentage function with accumarray
arrays,matlab,percentage,accumarray
This could be one approach: %// make all those non-zero values to zero AprefCORmask = AprefCOR == 1; %// you have done this [OTPCORorder1,~,idx] = unique(OTPCORorder,'stable'); %// Find number of each unique values counts = accumarray(idx,1); %// Find number of ones for each unique value sumVal = accumarray(idx,AprefCORmask); %// find...
Vectorization using accumarray
matlab,vectorization,accumulate,accumarray
Given: CylCoorsSample = [263.0000 184.2586 10.0000 264.0000 183.0417 10.0000 264.0000 182.1572 10.0000 82.0000 157.4746 11.0000 80.0000 158.2348 11.0000 86.0000 157.3507 11.0000 84.0000 157.7633 11.0000] PointValuesSample = [0.4745 0.5098 0.5020 0.4784 0.4510 0.4431 0.5804] You can use accumarray as follows (using the third output of unique to generate the required subs...
Summing rows by index using accumarray
Try this: M_sum = (L + eye(size(L,1)))*M; M_sum = triu(M_sum, 1); M_sum = M_sum + M_sum.'; This works because you already have matrix L, so matrix multiplication can be used to select and sum the rows of M. Using accumarray here would have two drawbacks: You'd need to apply find...