I would like to draw lines between the coordinates of the matrix below and then plot it, it should become an F.
F = ([0 2 2 7 7 2 2 8 8 0 0;0 0 8 8 10 10 14 14 16 16 0])
How can I do this?
You should simply be able to do this with
plot(F(1,:),F(2,:))
the style that you are plotting the data with has many options that you can refer to here http://www.mathworks.co.uk/help/matlab/ref/plot.html
Have you tried this?
plot(F(1,:),F(2,:),'k-.')
I dont have matlab here, but this must work!
Related
I have two vectors that describe a histogram: bin values/labels and bin count.
I'd like to import those into a Matlab histogram object so that I can change parameters more easily, such as the number of bins.
Here is a simplification what I have:
Center bin values:
BinValues(1:21) = [-10 -9 -8 -7 -6 -5 -4 -3 -2 -1 0 1 2 3 4 5 6 7 8 9 10];
and count values per bin
CountValues(1:21) = [ 16 12 3 21 7 8 2 6 0 3 4 6 1 8 3 25 16 5 7 10 16];
My actual histogram has 800000 bins, and I want to vary the number of bins.
In my simplified example above, it would be something like reducing the bins from 21 to 15 or 21 to 11.
What I have can be graphed as a simple bar graph.
bar(BinValues,CountValues);
But, if I want to experiment with different numbers of bins, I think it would be best to use the histogram function/object in Matlab, but I'm not sure how I do this from what I have.
OK Update:
I tried this:
h=histogram('BinEdges',[-10.5:10.5] , 'BinCounts', CountValues);
Now I have a nice histogram, but if I use fewerbins(h), I get an error saying I can't do that while BinCountsMode is in "manual". If I modify it to be in "auto" mode, then my original histogram disappears.
The brute force solution would be to generate a huge array with repeated values as dictated by binCount values, but that seems like a dumb way to solve this problem.
I'm using the following code to create a bar chart in matlab.
a = [1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9]
bar(a)
set(gca,'XTickLabel',{'one','two','three','four','five','six','seven','eight','nine','zero','one','two','three','four','five','six','seven','eight','nine'})
Code works fine except that x-axis labels don't appear on their corresponding position on the x-axis. How do I resolve this issue?
When you set XTickLabel, you are telling Matlab to replace the text where each tick currently is with new text that you provide. If you run only the first two lines, you will see that Matlab by default has put XTicks on 0:2:20. You can resolve the issue by first telling Matlab to put ticks for each individual bar, and then re-labeling these ticks:
a = [1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9]
bar(a)
set(gca, 'XTick', 1:length(a))
set(gca,'XTickLabel',{'one','two','three','four','five','six','seven','eight','nine','zero','one','two','three','four','five','six','seven','eight','nine'})
You will have a pretty cluttered x-axis at this point...you would want to look into rotating the XTickLabels with the rotateXLabels function from FileExchange or with the built-in functionality on Matlab14b and later.
I use matlab to plot a graph where instead of having x-axis increase monotonically, I have my own values. eg 5 14 8 9 12 7 etc.I use set (gca,'XTickLabel',num2str(mydata)) which generally works. However, when mydata is more than four or five digits, Matlab scales the graph and thus x-axis values no longer correspond to their intended points. Any ideas on how to prevent this scaling? To clarify, when I make the figure larger, it shows the plot as it should.
The problem is in your num2str() conversion:
mydata = 1:10;
num2str(mydata)
ans =
1 2 3 4 5 6 7 8 9 10
This means, that each tick will be labelled with this long 1 by n char array. The axes will then be resized to fit the labels inside the figure.
A solution is to create one label per row of a char array:
reshape(sprintf('%2d',mydata),2,[])'
ans =
1
2
3
4
5
6
7
8
9
10
Sort of solution is to write set(gca,'xtick',1:myDataVectorLength) before set (gca,'XTickLabel',num2str(mydata))
I have a 4x5 matrix, but I have some NaNs mixed in with the value. I really would like to change the NaNs to the nearest number, either above it or below it (because each column is disconnected to the next), like so:
A= NaN 10 35 150 1.5
4.2 11 NaN 149 1.45
4.8 NaN 36.1 153 1.3
5.3 13 40 147 NaN
I would like to have a function that would change the matrix to:
B= 4.2 10 35 150 1.5
4.2 11 35 149 1.45
4.8 11 36.1 153 1.3
5.3 13 40 147 1.3
I think I could use some sort of interpolation to do this, but Im not entirely sure how.
In this senario I am able to do it by hand but I will be using matrixes that are 1000sx1000s so couldn't do it then! I have looked for other examples of how to do this, but a lot of them change the NaNs to zeros.
Thanks in advance for the help.
Jordan
use inpaint_nans, a wonderful tool by John D'Errico that interpolate NaN elements in a 2-d array using non-NaN elements. It can also extrapolate, as it does not use a triangulation of the data. It offers several approaches to the interpolation, which give tradeoffs in accuracy versus speed and memory required.
I do not know if this function does exactly what you are expecting, but it might be helpful:
knnimpute
As an example
A = [1 2 5;4 5 7;NaN -1 8;7 6 0]
A =
1 2 5
4 5 7
NaN -1 8
7 6 0
you then call
knnimpute(A)
which yields
ans =
1 2 5
4 5 7
-1 -1 8
7 6 0
I'm using the CLUSTERGRAM object from the Bioinformatics Toolbox (ver 3.7).
MATLAB version R2011a.
I'd like to get permutation vectors for row and columns for clustergram, as I can do with dendrogram function:
x = magic(10);
>> [~,~,permrows] = dendrogram(linkage(x,'average','euc'))
permrows =
9 10 6 7 8 1 2 4 5 3
>> [~,~,permcols] = dendrogram(linkage(x','average','euc'))
permcols =
6 7 8 9 2 1 3 4 5 10
I found that the clustering is not the same from clustergram and dendrogram, most probably due to optimal leaf ordering calculation (I don't want to disable it).
For example, for clustergram from:
clustergram(x)
('average' and 'eucledian' are default methods for clustergram)
the vectors (as on the figure attached) should be:
permrows = [1 2 4 5 3 10 9 6 7 8];
permcols = [1 2 8 9 6 7 10 5 4 3];
So, how to get those vectors programmatically? Anybody well familiar with this object?
Do anyone can suggest a good alternative? I know I can create a similar figure combining imagesc and dendrogram functions, but leaf ordering is much better (optimal) in clustergram, than in dendrogram.
From looking at the documentation, I guess that get(gco,'ColumnLabels') and get(gco,'RowLabels'), where gco is the clustergram object, should give you the reordered labels. Note that the corresponding set-methods take in the labels in original order and internally reorders them.
Consequently, if you have used custom labels (set(gco,'RowLabels',originalLabels))
[~,permrows] = ismember(get(gco,'RowLabels'),originalLabels)
should return the row permutation.