# Dave B

### MathWorks

I am a software engineer at MathWorks. My work focuses on graphics and charting.

**Statistics**

RANK**90**

of 247,035

REPUTATION**1,206**

CONTRIBUTIONS

**0** Questions

**380** Answers

ANSWER ACCEPTANCE **
0.00%
**

VOTES RECEIVED**105**

RANK**12,947** of 17,225

REPUTATION**15**

AVERAGE RATING**4.50**

CONTRIBUTIONS**2** Files

DOWNLOADS **16**

ALL TIME DOWNLOADS**73**

CONTRIBUTIONS**0 Posts**

CONTRIBUTIONS**0** Public Channels

AVERAGE RATING

CONTRIBUTIONS**0** Highlights

AVERAGE NO. OF LIKES

**Content Feed**

spectrogram - auto settings for zlim are too wide

I'd guess that the color limits (i.e. CLim not ZLim) are tightly fitting the data, but you have a pixel or two that is making it...

3 days ago | 0

How to plot Histogram/bar graph for two data sets!!

I think there are a few ways to interpret your question. Do you mean you want to show two bar charts describing the histogram ...

6 days ago | 0

| accepted

Using multiple functions on a variable in a table

How about just initializing the new table variable first (e.g. with NaN values) and then populating it using your indices? T ...

6 days ago | 0

How to create a standalone executable file?

You can create standalone executables using MATLAB compiler. A product information page is here: https://www.mathworks.com/pro...

7 days ago | 0

3D surface plot

You can interpolate using a scatteredInterpolant to make a matrix over the range of X and Y and then use surf to draw it, but I ...

7 days ago | 1

| accepted

Splitting an array by the value

You can do this really easily with groupsummary x=[9 9 6 4 4 7 9 9 9 9 9 9 9 7 7 5 7 7 9 9 9 9 9]; y=[95.4508 85.2212 97.6083 ...

7 days ago | 3

How do I deidentify geoplot data?

You can turn off the Tick marks with the TickDir property on the GeographicAxes: geoplot(42+rand(10,1), -71+rand(10,1)) ax=gca...

8 days ago | 1

How to bin polar coordinates

The way you've written the code, the number of outputs in yBinned depends on how many of the bins of X were populated. edges = ...

8 days ago | 1

Using readtable to import a 5x1 column from Excel is missing one element. Why??

readtable detected the first value as a variable name Just add 'ReadVariableNames', false to your call to readtable (if you don...

9 days ago | 0

| accepted

How can I add x and y ticks to my imagesc graph?

When you use image (or imagesc), the values in the matrix are distributed evenly. Changing the ticks just changes what's labels....

9 days ago | 0

| accepted

Create closed curve from intersection between multiple curves

polyshape is pretty good for this, but you need to give it polygons not curves (i.e. define what's inside and what's outside). N...

9 days ago | 1

Conditionally replace numerical Array with Strings

This is happening because old_array is an array of doubles, you can't have a mix of strings and doubles in a regular (i.e. not c...

10 days ago | 0

cut of zeros from a matrix based on the longest non-zero row

Another way to phrase this question is to say you want to remove columns from the right side of the matrix if the whole column i...

10 days ago | 0

| accepted

RGB to Grayscale without using rgb2gray

You can choose many approaches for converting to grayscale. For instance you could weight the three colors equally: im=imread('...

10 days ago | 0

Use of 2D colormaps possible in Matlab?

There's nothing (that I know of) that provides this as a built-in utility in MATLAB, but it's pretty easy to do this kind of thi...

11 days ago | 0

| accepted

How to find correlations of corresponding rows of two arrays?

The correlations of columns are the diagonal of the correlation matrix, so you can Transpose your matrices on the way in to co...

11 days ago | 0

| accepted

How to add 3 x-axies onto a double subplot?

You can sort of fake this kind of thing with TiledChartLayout. The layout will keep your axes lined up. Starting simple, with...

12 days ago | 0

| accepted

Quiver plot appears upside down.

Images are normally shown in what's called ij coordinates, meaning (in the all positive number case) the top left corner is 0,0,...

12 days ago | 0

| accepted

y-axis are still inverted despite using fftshift

Your code doesn't run and you didn't include an image, but in general, when you call imagesc it will plot in ij coordinates, mea...

12 days ago | 0

Set default value for axes LabelFontSizeMultiplier

The pattern is the same, or maybe I misunderstand the question? When you get defaults from groot, it won't show all defaults a...

12 days ago | 0

| accepted

How to write a code in Matlab having two conditions?

In MATLAB indices start with 1: n=2048; %samples fs=1024; %sampling frequency T=1/fs; t = (0:n-1)*T; F=zeros(length(t)); ...

12 days ago | 0

| accepted

Invalid use of operator while trying to plot surface

A few issues: There's no .- in MATLAB, you use the dot to indicate you want a element-wise operation instead of a matrix operat...

12 days ago | 0

| accepted

Is it possible to give an categorical date set values so it can be used for a plot.

Note that you can plot categorical variables in a variety of ways. Passing your categoricals directly into your plotting functio...

13 days ago | 0

| accepted

Finding an old .m file

This one has the same author and function signature, although I obviously can't say for sure if it's the same! https://github.c...

13 days ago | 0

| accepted

How can I save graphics as pdf?

What you typed should work, it should save the current figure (gcf) as myfigure.pdf to the current directory. I'd recommend usi...

13 days ago | 1

| accepted

How to plot events over a signal?

@eyko you can plot the line with plot you can find the y values for the events with interp1, and plot them with plot or scatte...

13 days ago | 0

| accepted

Remove whitespace right to colorbar

Do you mean in an export or as displayed in the figure window? For the export, if you use the newer exportgraphics instead of ...

14 days ago | 0

| accepted

Difference between two statements

Switch doesn't provide new functionality but can make code easier to read and less complex: a='Apple'; These two blocks do t...

14 days ago | 1

how can I write a function

Your data look similar to this (as you've described them): load patients data=[{'name'} {'gender'} {'age'}; LastName Gender nu...

15 days ago | 0

| accepted

plotting and reversing axis in subplot

I think I only see a bar and two plots. Here's some abbreviated code: t=tiledlayout(2,2); % or you can even do t=tiledlayout(...

15 days ago | 0