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Walter Roberson


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49,273 2011 年以降の合計貢献数

I do not do free private consulting. If you want to bring my attention to something, send a link to the MATLAB Answers location.

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Anomaly with comments and rating in one file in File Exchange.
That is a new contribution that you are confusing with the related contribution https://www.mathworks.com/matlabcentral/filee...

約2時間 前 | 0

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The following error occurred converting from sym to double: Unable to convert expression into double array.
You initialized X_T to numeric (such as double precision), either explicitly or else that you happened to have a numeric one sit...

約11時間 前 | 0

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empty sym: 0-by-1 for Simultaneous equation
You are trying to solve 8 equations for 6 variables, but they are not consistent for all 8 equations. syms a b c d e x equ1 = ...

約11時間 前 | 0

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calculating an integral of complex function substituting data from excel
format long g e = [2.90234, 2.90343, 2.98021]; x = 3.01; k = 8.62*10^-5; T = 160; a = 0.2; fun = @(x,k,T,a,b,e) exp(-b.^...

約11時間 前 | 0

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How can I create a 2D contour Plot from X,Y,Z table?
num=50; Lpmax=700e-6; Lpmin=20e-6; Lr=2.77e-3; Cr=2.5e-9; f=1/(2*pi*sqrt(Lr*Cr*0.5)); ...

約12時間 前 | 0

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convert dd/mm/yyyy ro serial
d = readmatrix('excel.xlsx', 'D9:D7808'); d.Format = 'yyyy-MM-dd'; And if you need to, cellstr(d)

約12時間 前 | 0

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for loop return empty struct
syms x y z thickness = 0.1:0.01:0.30; unitcellsize = 1:0.1:6; num = max(size(unitcellsize)); step = 0.5; a = 0:step:unitc...

約13時間 前 | 0

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Selection months (winter) in a matrix
maxyear_to_calculate = 32; winter = permute(wind(:,:,[12,1,2],:), [3 1 2 4]); %month, long, lat, year nyear = size(winter,4...

約13時間 前 | 0

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How to open an excel file in read-only with actxserver?
https://excel.officetuts.net/en/vba/open-workbook-as-read-only https://www.mathworks.com/matlabcentral/answers/306813-problem-...

約14時間 前 | 0

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match time stamps index
v1 = [1610759986514 1610759986549 1610759986583 1610759986618 ] v2 = [1610759986540 1610759986589] interp1(v1, 1:length(v1), v...

約14時間 前 | 0

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xlswrite error; not working entirely or throwing up an error
Your variable Sample is empty, so when you construct filename = [RawImages '\' Sample '\' Sample] you are getting the result ...

約15時間 前 | 0

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How to change the date-format of an existing file ?
datetime('15-März-2019', 'Locale', 'de') So use readcell() with 'Locale', 'de'

約15時間 前 | 0

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Array indices must be positive integers or logical values.
derivative_x(a)=2*kons_G*rho_model*t*(-(1/(z2((x(a)-x0)^2/z2^2+1)))+(1/(z1((x(a)-x0))^2/z1^2+1))); %sudah dalam mGal MATLAB ...

約16時間 前 | 1

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Input files editing format
fid = fopen('input.txt', 'r'); nodedata = cell2mat( textscan(fid, '%*f,%f,%f', 'CommentStyle', {'*Heading', '*Node'}) ); e...

約17時間 前 | 0

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findpeaks [pks, locs] cannot detect NaN
if u ~= 0 Your u is a vector. The condition will be considered true only if all the entries are true, which is to say the same ...

約22時間 前 | 0

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where is the mistake?
What is being integrated? What is the lower bound? What is the upper bound? Your use of [-20 20 0 2] suggests that you are exp...

1日 前 | 1

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Multiple inputs using dialog box then inputs are placed into equation to get an output?
sigma_bw = str2double(P_bw) ./ (str2double(h_bw) .* str2double(L_bw));

1日 前 | 0

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Trying to use Symbolic Math Toolbox to prepare to solve two coupled second order ODEs
After edditing the ftotal to include the (t) for the Force functions Not a good idea. A = 0.1; w = 3; X_1 = 15; X_2 = 5;...

1日 前 | 0

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Comparing 2 Data sets (with different lenght)
No. The problem is not well defined. What could make the problem well defined is if there were time measurements associated wit...

1日 前 | 0

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Why do I get the Error: Array indices must be positive integers or logical values.
l starts at as 0. (notice you even coded it as being floating point rather than integer!) The assignment to help does not chang...

1日 前 | 1

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"Call the path to this directory <"Example"> "How to call a path?
That is a descriptive narrative. You installed MatConvNet somewhere . It does not need to be installed to any particular locat...

1日 前 | 0

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Reading Specific Columns of File
data = readmatrix('TheFileNameGoesHere.txt'); student_number = data(:,1); exam_1 = data(:,2); However you should consider ins...

1日 前 | 0

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How to make the keyboard keys on the computer unable to be used to input the Matlab GUI calculator.
you could create one radio button for each different value that you wanted to represent you could create one push button for ea...

2日 前 | 0

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How to change color in Graph (jet)
% Define domain dx = 0.001; L = pi; x = (-1+dx:dx:1)*L; n = length(x); nquart = floor(n/4); % Define function f = x; h1 =...

2日 前 | 0

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Matlab does not plot the function
GH_num= [1 2 3]; GH_den= [4 5 6 7 8]; GH_w=[]; wvals = 2*pi*logspace(-1,3,1000); %NEW for w = wvals ...

2日 前 | 0

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How do I find the indices of NaN values in a cell array?
The below accounts for the possibility of multiple nan blocks. It does not, however, account for the possibility that the first...

2日 前 | 0

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monts in year sequence, string, matrix
Convert to a timeseries() object and use retime() Or: Data = rand(365,1); Data_timestamp = datetime(2021, 1, 1:365).'; %use ...

2日 前 | 1

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Index exceeds matrix dimensions. in for loop !
for i=1:Np x(: , i+1) = f(x(: , i) , U(:,i)); That needs to access up to the Np'th column of U Cost ([1;1;1;1;1;1] , ...

2日 前 | 0

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Keeping track of the Index while using "cell2mat" function
key = cell2mat((arrayfun(@(IDX) [repmat(IDX, size(a{IDX},1), 1), (1:size(a{IDX},1).']) , 1:numel(a), 'uniform', 0)); Now index ...

2日 前 | 0

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Can't plot a graph no matter what I do
if check1 == 1 && check2 ==2 && check3 ==1 elseif check1 == 1 && check2 ==2 && check3 ==1 Those are the same condition...

2日 前 | 1

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