get value from stem graphic - matlab

let us suppose that we have following graph of singular value distribution
which was given by following command
stem(SV)
SV_singular values,from visually of course we can find approximate values of singular values,but is there any possibility to get values from graph itself?of course someone may say that if we have SV,we can directly access,but i want just graphicl tool to get it from picture itself,for example like this
b=stem(SV);
but when i type b,i am getting following number
b
b =
174.0051
it is matlab self learning,so please help me to learn how to find values from graphics in matlab

The value stored in your variable b is a handle to the current axes. You can access the properties of this axes using get. To access the values in the plot, you can use
b=stem(SV);
values = get(b, 'ydata');

Related

Retrieve Gradient of Reference Line Generated by probplot

I am generating probability plots for a number of data sets in matlab.
I am plotting them using probplot with a weibull distribution reference line
data = [1,1,1,1,2,2,2,3,4,5,3,3,2,2,1,3,5,7,2,4,2] ;
h = probplot('weibull',data) ;
This function as per the matlab documentation returns a graphic array object. This appears to only contain the original data and not the reference line.
Is there any way of retreiving information about about this reference line without plotting it and indiviually extracting it using the figure tools (very much not an option I'd like to go down as there are potentionally hundreds of plots to go through).
I can see there is wblplot that returns a line array of 3 lines, one of which is the original data and one of the others is likely the reference the line however I will have to try different distributions to fit further down the road and would prefer to keep a generic approach.
You are wrong!
data = [1,1,1,1,2,2,2,3,4,5,3,3,2,2,1,3,5,7,2,4,2] ;
h = probplot('weibull',data) ;
b=h(2);
figure
plot(b.XData,b.YData)
h is a graphic array object, so its an array. The first element contains the original data, but the second h(2) contains the reference line.

Check values of an iddata in Matlab

Good morning,
I want to ask you about an iddata object in Matlab. I want to know how it is possible to check its values (the y1 output). This is my code:
data = iddata(M4,M4,0.01);
sys = arx(data,[4 1 1])
K=6;
hf2=forecast(sys,data,K);
And I want to know the values of the forecast output, the 'hf2' (but it is an iddata object and I don't know how to do it). I have seen that I can plot it but I don't know how to know the values.
Thanks in advance,
The function properties allows you to displays the names of properties of a matlab object. Then you can access the propertie's value with the command: object.properties.
For example: hf2.OutputData
Also read the doc about the object iddata, all the properties are explained.

How to access the variable range for leaf node in classregtree of matlab?

I used classregtree to fit a tree to my data set in order to classify the data. All of predictors and the response are quantitative. I want to save the range of each variable on terminal nodes, because I am gonna use those ranges in another function.
So is there any way that I can have access to those ranges? I can see the variable ranges in view(tree) plot but I need to save them in like a matrix to use them.
I am not totally sure that this is what you were asking for but this gives you the split criterions for all trees
B = TreeBagger(nTrees,M,tag, 'Method', 'classification','OOBPred','on');
view(B.Trees{1:B.NTrees})
where M is your trainig data set and tag are the classes.

What's the complete structure of a figure handle object?

Mathworks has done it again: my ancient R2012 (as bestowed by my company) returns a nice set of doubles identifying the figure window numbers in response to
currhandles=findall(0,'type','figure');
Now I got a fellow remotely IM-ing me 'cause the code I gave him fails under R2015 because findall now returns a structure for the figure handle. I can't play w/ his system (no RDC) and the mathworks documentation pages don't appear to specify the elements of the figure handle structure. In particular, I'd like to know if I can still retrieve the figure window number. Anyone know?
Of course.
currhandles(:).Number
will return all numbers as a comma-separated list.
Or specify a number you want:
currhandles(1).Number
The order appears to be the inverse order of initialization.
Alternatively you can define two anonymous functions to get an array directly:
figure(1); figure(2); figure(42);
getNumbers = #(x) [x.Number];
getFigureNumbers = #() getNumbers([findall(0,'type','figure')]);
getFigureNumbers()
ans =
42 2 1

matlab zplane function: handles of vectors

I'm interested in understanding the variety of zeroes that a given function produces with the ultimate goal of identifying the what frequencies are passed in high/low pass filters. My idea is that finding the lowest value zero of a filter will identify the passband for a LPF specifically. I'm attempting to use the [hz,hp,ht] = zplane(z,p) function to do so.
The description for that function reads "returns vectors of handles to the zero lines, hz". Could someone help me with what a vector of a handle is and what I do with one to be able to find the various zeros?
For example, a simple 5-point running average filter:
runavh = (1/5) * ones(1,5);
using zplane(runavh) gives an acceptable pole/zero plot, but running the [hz,hp,ht] = zplane(z,p) function results in hz=175.1075. I don't know what this number represents and how to use it.
Many thanks.
Using the get command, you can find out things about the data.
For example, type G=get(hz) to get a list of properties of the zero lines. Then the XData is given by G.XData, i.e. X=G.XData.
Alternatively, you can only pull out the data you want
X=get(hz,'XData')
Hope that helps.