I have code that creates a portfolio in matlab by merging two time series. How do I retrieve a vector of Headers for the funds such that I get a vector with the fund names from 'Port'?
Fund1ts=fints(Fund1Dates,Fund1Data,'Fund1');
Fund2ts=fints(Fund2Dates,Fund2Data,'Fund2');
%CREATE PORTFOLIO
Port=merge(Fund1ts,Fund2ts,'DateSetMethod','Intersection');
If you look at Port in the Command Window they are present. However if you open Port from Workspace Window then only the data exists hence my problem in retrieving it.
Thank you.
As Hugh Nolan also suggested in a comment, this should get you the names you are after:
fnames = fieldnames(Port, 1)
From the documentation:
fnames = fieldnames(tsobj, srsnameonly) returns field names depending upon the setting of srsnameonly. If srsnameonly is 0, the function returns all field names, including the common fields: desc, freq, dates, and times. If srsnameonly is set to 1, fieldnames returns only the data series in fnames.
Hence the 1 in the code-snippet above. It will return only Fund1 and Fund2.
Edit
It appears that there are two functions called fieldnames in Matlab:
The 'standard' function fieldnames:
names = fieldnames(s)
names = fieldnames(obj)
names = fieldnames(obj,'-full')
The function fieldnames which is part of the Financial Toolbox:
fnames = fieldnames(tsobj)
fnames = fieldnames(tsobj, srsnameonly)
If called with one input argument, they both operate similarly. However, for future readers of this answer: The particular answer given above works only for the Financial Toolbox-version of the function.
Related
In my code, I have a structure and in a field of it, I want to sort its values.
For instance, in the field of File_Neg.name there are the following values, and They should be sorted as the right values.
File_Neg.name --> Sorted File_Neg.name
'-10.000000.dcm' '-10.000000.dcm'
'-102.500000.dcm' '-12.500000.dcm'
'-100.000000.dcm' '-100.000000.dcm'
'-107.500000.dcm' '-102.500000.dcm'
'-112.500000.dcm' '-107.500000.dcm'
'-110.000000.dcm '-110.000000.dcm'
'-12.500000.dcm' '-112.500000.dcm'
There is a folder that there are some pictures with negative labels in it (above example are labels of pictures). I want to get them in the same order as present in the folder(that's mean the Sorted File_Neg.name). But when running the following code the values of Files_Neg.name load as the above example (left: File_Neg.name), while I want the right form.
I have also seen this and that but they didn't help me.
How to sort values of a field in a structure in Matlab?
Files_Neg = dir('D:\Rename-RealN');
File_Neg = dir(strcat('D:\Rename-RealN\', Files_Neg.name, '\', '*.dcm'));
% when running the code the values of Files_Neg.name load as the above example (left: File_Neg.name)
File_Neg.name:
This answer to one of the questions linked in the OP is nearly correct for the problem in the OP. There are two issues:
The first issue is that the answer assumes a scalar value is contained in the field to be sorted, whereas in the OP the values are char arrays (i.e. old-fashioned strings).
This issue can be fixed by adding 'UniformOutput',false to the arrayfun call:
File_Neg = struct('name',{'-10.000000.dcm','-102.500000.dcm','-100.000000.dcm','-107.500000.dcm','-112.500000.dcm','-110.000000.dcm','-12.500000.dcm'},...
'folder',{'a','b','c','d','e1','e2','e3'});
[~,I] = sort(arrayfun(#(x)x.name,File_Neg,'UniformOutput',false));
File_Neg = File_Neg(I);
File_Neg is now sorted according to dictionary sort (using ASCII letter ordering, meaning that uppercase letters come first, and 110 still comes before 12).
The second issue is that OP wants to sort according to the magnitude of the number in the file name, not using dictionary sort. This can be fixed by extracting the value in the anonymous function applied using arrayfun. We use str2double on the file name, minus the last 4 characters '.dcm':
[~,I] = sort(arrayfun(#(x)abs(str2double(x.name(1:end-4))),File_Neg));
File_Neg = File_Neg(I);
Funnily enough, we don't want to use 'UniformOutput',false any more, since the anonymous function now returns a scalar value.
I'm trying to change output names using for in Matlab. I'm reading daily files, so I'd like the outputs to also have the day printed on their name. This is a simplification of what I've got so far:
day=['1','2','3','4','5'];
for i=1:length(day)
namefile=['datafromday',num2str(day(i)),'.nc'];
[var1,var2,var3]=read(namefile);
var1_*=var1;
var2_*=var2;
var3_*=var3;
end
The * marks where I want to have the day number on. I've tried the same combination as in namefile but was unsuccessful.
Any ideas? Thank you!
I suggest you use a 2D cell array instead of separate variables. First index of the cell array will correspond to day, second will correspond to namefile. (Also, don't use var as a variable name, as there is a function with that name).
day = ['1','2','3','4','5'];
vars = cell(numel(day),3); %// change "3" as needed
for i = 1:length(day)
namefile = ['datafromday',num2str(day(i)),'.nc'];
[vars{i,:}] = read(namefile);
%// Now the file names are in vars{i,1}, vars{i,2} etc
end
I am using ode15s to solve a DAE problem. I give through odeset the Mass Matrix and some more info:
opts=odeset('Mass',M,'MassSingular','yes','MStateDependence','none');
I calculate also Jpattern from a previous run. To feed it to the function, I could write once again
opts=odeset('Mass',M,'MassSingular','yes','MStateDependence','none', 'JPattern',JPat);
Is there a way to modify that single parameter and keep the rest of the structure?
I tried
opts.JPattern = JPat;
But it is not working.
You can probably do something like:
opts = odeset('Mass',M,'MassSingular','yes','MStateDependence','none');
opts = odeset(opts,'JPattern',JPat);
This is using the syntax (see the documentation):
options = odeset(oldopts,'name1',value1,...) alters an existing
options structure oldopts. This sets options equal to the existing
structure oldopts, overwrites any values in oldopts that are
respecified using name/value pairs, and adds any new pairs to the
structure. The modified structure is returned as an output argument.
I am trying to find a better solution to calculation using data stored in table. I have a large table with many variables (100+) from which I select smaller sub-table with only two observations and their difference for smaller selection of variables. Thus, the resulting table looks for example similarly to this:
air bbs bri
_________ ________ _________
test1 12.451 0.549 3.6987
test2 10.2 0.47 3.99
diff 2.251 0.078999 -0.29132
Now, I need to multiply the ‘diff’ row with various coefficients that differ between variables. I can get the same result with the following code:
T(4,:) = array2table([T.air(3)*0.2*0.25, T.bbs(3)*0.1*0.25, T.bri(3)*0.7*0.6/2]);
However, I need more flexible solution since the selection of variables will differ between applications. I was thinking that better solution might be using either varfun or rowfun and speficic function that would assign correct coefficients/equations based on variable names:
T(4,:) = varfun(#func, T(3,:), 'InputVariables', {'air' 'bbs' 'bri'});
or
T(4,:) = rowfun(#func, T(3,:), 'OutputVariableNames', T.Properties.VariableNames);
However, the current solution I have is similarly inflexible as the basic calculation above:
function [air_out, bbs_out, bri_out] = func(air, bbs, bri)
air_out = air*0.2*0.25;
bbs_out = bbs*0.1*0.25;
bri_out = bri*0.7*0.6/2;
since I need to define every input/output variable. What I need is to assign in the function coefficients/equations for every variable and the ability of the function to apply it only to the variables that are present in the specific sub-table.
Any suggestions?
I want to create a structure with a variable name in a matlab script. The idea is to extract a part of an input string filled by the user and to create a structure with this name. For example:
CompleteCaseName = input('s');
USER WRITES '2013-06-12_test001_blabla';
CompleteCaseName = '2013-06-12_test001_blabla'
casename(12:18) = struct('x','y','z');
In this example, casename(12:18) gives me the result test001.
I would like to do this to allow me to compare easily two cases by importing the results of each case successively. So I could write, for instance :
plot(test001.x,test001.y,test002.x,test002.y);
The problem is that the line casename(12:18) = struct('x','y','z'); is invalid for Matlab because it makes me change a string to a struct. All the examples I find with struct are based on a definition like
S = struct('x','y','z');
And I can't find a way to make a dynamical name for S based on a string.
I hope someone understood what I write :) I checked on the FAQ and with Google but I wasn't able to find the same problem.
Use a structure with a dynamic field name.
For example,
mydata.(casename(12:18)) = struct;
will give you a struct mydata with a field test001.
You can then later add your x, y, z fields to this.
You can use the fields later either by mydata.test001.x, or by mydata.(casename(12:18)).x.
If at all possible, try to stay away from using eval, as another answer suggests. It makes things very difficult to debug, and the example given there, which directly evals user input:
eval('%s = struct(''x'',''y'',''z'');',casename(12:18));
is even a security risk - what happens if the user types in a string where the selected characters are system(''rm -r /''); a? Something bad, that's what.
As I already commented, the best case scenario is when all your x and y vectors have same length. In this case you can store all data from the different files into 2 matrices and call plot(x,y) to plot each column as a series.
Alternatively, you can use a cell array such that:
c = cell(2,nufiles);
for ii = 1:numfiles
c{1,ii} = import x data from file ii
c{2,ii} = import y data from file ii
end
plot(c{:})
A structure, on the other hand
s.('test001').x = ...
s.('test001').y = ...
Use eval:
eval(sprintf('%s = struct(''x'',''y'',''z'');',casename(12:18)));
Edit: apologies, forgot the sprintf.