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# Peter Perkins

### MathWorks

Last seen: 17 days ago Active since 2011

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Subset timetable by specific time windows/periods
This post is more than a year old, but I'm responding in hopes that it might help anyone who looks at this. First, I don't unde...

19 days ago | 0

ismember: Find matching entries in table columns (and add entry from matching row)
This is a one-liner with tables: >> A = table([1;3;5]) A = 3×1 table Var1 ____ 1 3 5 >> ...

1 month ago | 0

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Using index to match rows of table
Lukas, you don't say what you actually need to do after getting those rows, but I'm going to suggest that you should be using ro...

1 month ago | 0

How to Create txt output from multiselect file by using readtable?
This code DATE = T{:,1}; TIME = T{:,2}; TIME.Format = 'hh:mm:ss'; DOH = T{:,3}; ...

1 month ago | 0

How to convert a minutes elapsed vector to time (hh:mm)?
"continous 24 hour measurement" sounds like you are dealing with time of day. If you add 600 minutes to hours(16), you will get ...

1 month ago | 0

Insert new row with values in a table before specific values
It is possible to just use tabular subscripting to insert these rows. This is kind of old school MATLAB. Don't know if it is eas...

1 month ago | 0

Plot a timetable for charging electric vehicles
Sure. It looks like you want to overlay not only all stands, but also all days on one (24 hour?) time of day axis. That makes it...

1 month ago | 0

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How to separate two graphs plotted in one figure into two separate figures?
If spikes were two separate variables in a timetable (see splitvars), this would just be stackedplot(neural).

2 months ago | 0

How do I add a label on each bar of a multiple bar chart? I want to add specific times as labels.
I bet there's a way to simplify the arguments to your bar command. What about something like bar(T_Smooth.X(1:4),T_Smooth{1:4,[...

2 months ago | 0

Operator '==' is not supported for operands of type 'table'.
There are a couple of problems. c is a table, so R = c(:,"SAPID") is also a table, with only one variable. A table is a contai...

2 months ago | 1

Dividing grouped data into equally sized subgroups
>> x = rand(16,1); >> g = repmat((1:2)',8,1); >> t = table(g,x) t = 16×2 table g x _ _______ ...

2 months ago | 1

Trying to get time between each start and stop & total time per day from a text file.

2 months ago | 0

How to vertically join differently sized tables?
One way is to "assign off the end": >> table1 = table(1,70,175,29,datetime(1992,7,1),"M",'VariableNames',{'Num','Weight','Heigh...

2 months ago | 1

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Connect correct temperature to another table based on time
Use timetables. It's a one-liner: >> A = timetable(datetime(["13-aug-2020";"14-aug-2020";"15-aug-2020"]), [13.8; 12.2; 8.5]) ...

2 months ago | 1

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bar graph with non numerical x-axis
Simon's solution is one way to do it. But using categorical just to label the bars is kind of an abuse of categorical, which is ...

2 months ago | 0

How to treat a duration array in a for loop?
Judith, I can't really follow what you are doing, but if you have timestamped data, you should be using a timetable, and then re...

2 months ago | 1

Reorganize table and make groups of rows to columns
You need unstack: >> Date = datetime(1963,[1;2;3;1;2;3;1;2;3],[31;28;29;31;28;29;31;28;29]); >> Permno = [10065;10065;10065;10...

2 months ago | 2

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Delete rows in cell aray where there is anything in one collum.
A cell array is the wrong way to store these data. You want a table, or probably a timetable. The fact that you say, "the name o...

2 months ago | 0

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Prevent overwriting within a for loop in 3D-motion tracking
You may just want T = table(); for ... ... T = [T; readtable (thisFile)];

2 months ago | 0

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How to convert the number of seconds from an epoch into UTC using the datetime function.
Matthew, this is easier than you think. In MATLAB, 'TimeZone','UTC' is sort of a ficticious timeline that pretends that leaps se...

2 months ago | 0

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How to plot only the matches of two different datetime?
If all you have are two datetime vectors, you can use intersect to find the common values. But I'm guessing you have other data ...

2 months ago | 0

How to filter the data.
Not sure how you are getting those data into MATLAB, but I suggest that you figure out why you have a cell array. You want a tab...

2 months ago | 0

extracting columns from multiple cell arrays consist of table data
If you've read two "similar" tables into a 2x1 cell array, best ting to do is to vertvat them outside the loop: >> C = {array2t...

2 months ago | 1

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split cell in 2 columns
Use cellfun, two possibilities: function [val1,val2] = myfun1(x) val1 = x(1); if isscalar(x) val2 = 0; else val2 =...

2 months ago | 0

How do I find the corresponding date/time value of the maximum of my data in a table?
This is a pretty common question, so I'm gonna show a bunch of stuff in hopes others can find it useful. Let's start with a sim...

2 months ago | 0

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how to sort a cell array inside a struct?
I think you would be better off with a table than a struct. Name_Code = table(IDs, C,'VariableNames',["Name" "Codes"]) Name_Co...

2 months ago | 0

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Error with splitting table into separate columns.
This is an application of unstack and then stack. The code looks a lot more complicated than it might if I hard-coded in sizes, ...

2 months ago | 0

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Coordinate interpolation with time
This line of code pf = polyfit(Lat(:,1) Lat(:,2)], [(Long(:,1) Long(:,2)] %Coordinates is not valid syntax for several reasons...

2 months ago | 0