Community Profile # KSSV

Last seen: Today Active since 2011

https://sites.google.com/site/kolukulasivasrinivas/ Professional Interests: Mathematical Computing

Programming Languages:
Python, MATLAB, Fortran
Spoken Languages:
English, Hindi, Telugu

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Error about preallocating for speed
You need to proceed likt his: % Alpha Fe a = []; T = 25:5:1000 ; nT = length(T) ; a = zeros(nT,1) ; for i = 1:length(T...

1 hour ago | 0

Unsing string for indexing though structures
i = 108; % A = ((0.1255)/2)^2*pi; % ml_in_m3 = 1e-6; while i <= 108 pfad = '...'; s = strcat(pfad,'Test3_',string(i...

7 hours ago | 0

create cell array by extracting all the same row from multiple matrix
D = cell(105,5) ; for i = 1:105 D{i} = [A(i,:) B(i,:) C(i,:)] ; end Or D = [A B C] ; D = num2cell(D,2) ;

12 hours ago | 0

Extract a range of frequencies from a vector/array
new_value_from_fnew = fnew(fnew == 10e+009 | fnew > 30e+009); % <--- replace = with ==

1 day ago | 0

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Trying to define a circle within a matrix
[X,Y] = meshgrid(1:50) ; C = [mean(X(:)) mean(Y(:))] ; R = 10 ; th = linspace(0,2*pi) ; x = C(1)+R*cos(th) ; y = C(2)+R...

2 days ago | 0

How to find coordinate if only x is given?
Rm = sqrt(x.^2+y.^2) ; % get radius from mexh (x,y) R = 75 ; tol = 10^-3 ; idx = find(abs(Rm-R)<tol) ; iwant = [idx x(idx)...

2 days ago | 0

How to read all CSV files within a folder, combine into one master file using columns, and edit column headers?
folderPath1 = 'C:\Users\matav\Documents\MATLAB\example'; cd(folderPath1); % opens path of the folder csvFiles = dir('*.csv') ;...

2 days ago | 0

How do these Python commands have to look in Matlab to calculate A and B and show me the two results?
A = 10+10; B = A+10 ; fprintf('A = %f, B = %f\n',A,B) ;

2 days ago | 0

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Read multiple CSV files from different folders uing readtable
thepaths = {p1,p2,p3} ; for i = 1:3 % loop for ech folder csvFiles = dir([thepaths{i},'\*csv']) ; % get ll csv files in ...

3 days ago | 0

ncfiles = dir('*.nc') ; N = length(ncfiles) ; for i = 1:N thisfile = ncfiles(i).name ; % do your calculation end...

5 days ago | 0

streamline function gives empty output
Try replacing NaN's in u, v with zero and use stream2.

5 days ago | 0

Graph appears blank but the equation and code are correct.
H_k_eq = @(k) (exp(-pi.*k.^2)) ./ (exp(-pi.*k.^2) + exp(-pi.*(4.*k).^2)); %<-- element by element division Range = -0.5:.01:...

5 days ago | 1

Solving Unknowns with Symbolic Toolbox
A = [1 1 0 0 ; 0 0 1 1 ; 1 0 1 0 ; 0 1 0 1] ; b = [3;7;4;6] ; x = pinv(A)*b Note that rank of A is 3, so...

5 days ago | 0

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Plotting a 3D matrix with plot3
LambdaL = linspace(0.000001,0.0001,20); % [Matrix in X axis] LambdaT = linspace(0.000001,0.0001,20); % [Matrix in Y axis] ...

6 days ago | 0

Write a program to input 3 integer digits (from 100 - 999), then in the numbers letters in hundreds, tens, and units ?
Read about input and see this file exchange: https://in.mathworks.com/matlabcentral/fileexchange/47221-number-to-words

7 days ago | 0

How to Plot Excel file in MatLab
Load the excel file into MATLAB using readtable. If you have time series; use plot. If 2D use pcolor. If scattered data use scat...

7 days ago | 0

Multiple data file loading to run some functions
fname = dir('*.txt') ; % gets all text files N = length(fname) ; for i = 1:N txtFile = fname(i).name ; % load t...

7 days ago | 0

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Gradient of a Vector function
syms x y z f(x,y,z) = x+y^3 ; gradient(f)

8 days ago | 0

Rotating X & Y Data
p1 = rand(2,1) ; p2 = rand(2,1) ; %%rotation matrix th = 90*pi/180 ; R = [cos(th) -sin(th) ;sin(th) cos(th)] ; %%rotate po...

8 days ago | 0

Finding equilibrium points for an ODE system
tol = 10^-5 ; % change the tolerance idx = abs(cdot)<tol & abs(cddot)<tol ; [cdot(idx) cddot(idx)]

8 days ago | 0

Hello I'm getting this warning "Variable 'x1' might be set by a nonscaler operator".
You case x1, x2 are vectors and you cannot use the condition like that. You have to use like shown below. n = -5:5; A = 0.8...

8 days ago | 0

connecting points with the same value
REad about contour Z = peaks(100) ; pcolor(Z) ; shading interp hold on contour(Z,[1 1],'k') % show/join the value 1 with ...

8 days ago | 0

How to use imported data with trapz( )
T = readtable('https://in.mathworks.com/matlabcentral/answers/uploaded_files/1129920/H182%20Drag.csv') ; x = T.(1) ; y = T.(2)...

8 days ago | 0

Join strings together with '_' between them
a = {'A11';'A12';'A21';'A22';'A23';'A24'}; b = {'A300';'A5300';'A291';'A5291'}; a1 = repmat(a,length(b),1) ; b1 = repelem(b...

8 days ago | 0

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How do I compute the standardized sample mean from this data?
N = 10000; a=0; b=1; x = a+(b-a)*rand([N,1]); lambda = 1; Y = -log(x)/lambda; Y_std = (Y-mean(Y))/std(Y) ; mean(Y_std)

8 days ago | 0

Create a Matrix with Euclidian Distances between Coordinates
A = rand(8,2,3) ; B = permute(A,[1 3 2]); B = reshape(B,[],size(A,2),1) ; iwant = squareform(pdist(B))

9 days ago | 1

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Use a command only once
Make theta_b also a input variable. % Inputs are reference voltage Vdr and Vqr,reference current ,Idr and Iqr % and measured ...

9 days ago | 0