Community Profile # Brendan Hamm

### MathWorks

Active since 2015

Profession: Training Engineer at the MathWorks.
Interests: Computational Finance, Stochastic Processes, Probability & Statistics, Optimization, Machine Learning and MATLAB.

All views expressed in my posts are my opinions and not necessarily those of the MathWorks.

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Random vector non repeated otherwise create new vector
p = perms(1:5); idx = randi([1,size(p,1)]); selection = p(idx,:)

3 years ago | 0

Is there a difference between declaring a class property "Dependent" versus "Dependent = true"?
There is no difference. For attributes which are binary (true/false) then just putting the attribute name is the same as togglin...

3 years ago | 1

GradientDescent algorithm returning error: left and right side different number of elements
I would put a break point on the line: error = ((hypothesis - y).^2); I would assume that the size of hypothesis and y are dif...

3 years ago | 0

Exporting a figure with an opaque legend box but no visible edge
You can modify this by setting the EdgeColor to none. set(Lgd,'EdgeColor','none');

3 years ago | 1

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fitcsvm decision boundary equation
Generate some data for the classes rng('default') n = 100; X = [2 + 0.5*randn(n,2);... 3 + 0.6*randn(n,2)]; Y = [zeros(...

3 years ago | 1

keep getting "too many output arguments" error while using the optimization tool box
Your non-linear constraint function needs to pass 2 output arguments back with the following calling signature: function [c,ceq...

3 years ago | 1

How many hours do MATLAB self-paced courses last about?
Each of the self-paced courses will show a "detailed course outline" on the course page. These will list the number of "days", w...

3 years ago | 5

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How do I make a polynomial regression of data points and afterwards calculate the prediction accuracy
I notice a few issues. Based on the second line of your portion, I assume that you mean to call the variable PressureDiffSquared...

3 years ago | 1

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How plot a matrix for Naive Bayes classifier?
The |heatmap| function was introduced in 2017a. The |imagesc| function will work though. To display the numeric counts you will ...

3 years ago | 0

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The is no 'linearFit' function
This is a helper function provided at the end of the documentation in the <https://www.mathworks.com/help/predmaint/examples/_...

3 years ago | 1

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Good coding practice / refactoring to remove multiple inheritance
1. There is no "best" practice as this depends on why you made the initial decision to perform multiple inheritance and then lat...

3 years ago | 0

Is there any way to generate code for nntool?
The nntool does not allow this, but you can generate the code for setting up and training a classification problem, which I assu...

3 years ago | 0

Problem with p-value calculation for Spearman's rho correlation analysis
I will notify the development team of your request. In the meantime, if anyone is experiencing the same issue, it may be worth e...

3 years ago | 0

the H and P value of standard normal distribution
The lillietest tests the null hypothesis that the *data* comes from a normal distribution against the alternative that it does n...

3 years ago | 0

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I am using Matlab R2016a. I want add alexnet but add on explorer not shown any thing what i do please suggest
You will need to upgrade to a new version of MATLAB as this was not released until R2016b.

4 years ago | 0

How can I post an order request via API?
Hi Fabio, Without a pair of keys myself I cannot duplicate the |auth| portion of this. I suspect this woudl be done with the ...

4 years ago | 0

Weight and Bias from a Neural Network
I'm not sure why you would get a 0x1 empty double column vector. You may need to post some code to help figure this piece out. ...

4 years ago | 4

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How to speed up code for converting an array of strings to array of numbers
I am not sure how much of a speedup to expect in the conversion, but I would highly consider using <https://www.mathworks.com/he...

4 years ago | 1

What is wrong with my while loop?
Your problem is that the result of X(:,:,1) == X(:,:,b) or X(:,:,1) ~= X(:,:,b) will return a logical matrix th...

4 years ago | 1

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how to parallelize separate matrix-matrix multiplications?
Unless you are working on a cluster, I would not expect to see any speed up from parallelizing such operations. The reason for t...

4 years ago | 0

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How to change XTick Labels in a heatmap
A |heatmap| stores the labels in the |XDisplayLabels| property. It is not a |matlab.graphics.axis.Axes|, but rather a |matlab.gr...

4 years ago | 1

How do i normalize data in neural networks ? feauture by feature or hole data in one step?
Yes. Data would be normalized feature by feature as it would not make sense to divide something in units of C by something in un...

4 years ago | 0

Non linear optimization using MATLAB
There is clearly an issue with the question as the provided solution does not provide a valid answer to the problem. That being ...

4 years ago | 0

how can i make alexnet accept 277x277x1 images
You can resize an image with the |imresize| function. Now since your images are of size 277x277x1 I will assume they are graysca...

4 years ago | 1

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Saving strings of different sizes in one variable
This is where the cell data type is used. names = {'folder1 xxx\name 1.txt';'folder2 xxxxxxx\name 2.txt';name_3 = 'folder3 ...

4 years ago | 0

runtime for t-copulafit
Your best option is to change the method for negative log-likelihood calculations. This is only recommended for large samples. ...

4 years ago | 1

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p values from correlation matrix using nancov
The corrcoef function accepts Name-Value pair inputs to handle missing data. [r,p] = corrcoeff(B,'rows','complete') ...

4 years ago | 1

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testing significan linier trend
If you are using a version equal to or later than 2013b than you can use the |fitlm| function which prints the relevant t-statis...

4 years ago | 0

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