I have a MATLAB code and I do how understand how it works.In the main code
%Tuning
tunestruct = {samplefunc,numreps,data_type,MS_criterion};
[Xtrain,optk,optsig2,tuningExtras] = tuneSKSC(data,kernel_type,maxk,tunestruct);
tuneSKC.m starts with
function [Xtrain,optk,optsig2,extras] = tuneSKSC(datastruct,kernel,maxk,tunestruct)
My question is what is tunestruct?Then, are data,kernel_type,maxk,tunestruct arguments for function?
I have pasted tunestruct.m
http://pastebin.com/cFH433Md
tunestruct is actually a cell array made of a bunch of other variables.
A cell array is a data type with indexed data containers called cells, where each cell can contain any type of data. Cell arrays commonly contain either lists of text strings, combinations of text and numbers, or numeric arrays of different sizes.
The reason of making a cell array instead of passing those arguments as separate values each times, is that the code has a very specific pattern for handling this set of parameters, in case they are not passed as arguments, as described in this code segment you've provided:
if exist('tunestruct','var')
if ~iscell(tunestruct)
tunestruct = {tunestruct,1};
end;
if(strcmp(tunestruct{1},'furs'))
tunestruct{2} = 1; %furs is deterministic, only one repetition is enough
end
s1 = ~strcmp(tunestruct{3},'net_unw') && strcmp(tunestruct{4},'Modularity');
if(s1)
tunestruct{4} = 'AMS'; %Modularity is used for unweighted network data
warning('\nNot possible to use Modularity, using AMS instead...');
end
end;
Related
I've been stuck with this for a while and I couldn't find something similar asked previously (or I have failed in doing so)
My situation is fairly simple: I have a cell array of objects. They are all the same object and I have a get function for this kind of object which is: get (obj, attr), where obj is the object in question and attr is a integer from 1-6. Depending on the number the get function returns the corresponding attribute.
I would like to obtain all of my "position" attributes from all my objects which are in the corresponding cell array (this would be attr = 2). I know that cellfun performs a function on all cells, but the question is, how do I use my get function here for all my objects, taking into account that the function is get (obj, attr) ?
Thanks in advance
Firstly, by using get as a custom function you are shadowing the built-in get function - this is bad practise!
With this in mind, and to avoid confusion with the built-in get function which has similar syntax, I'm going to use getattr as a stand-in for your custom function which accpets an object and an integer 1 to 6.
pos = cellfun( #(obj) getattr( obj, 2 ), myCellOfObjects, 'uni', 0 );
By specifying 'uni', 0, the output doesn't have to be scalar and will be put into a cell array. This is useful when, for example, you have a multi-element array for your position.
This is equivalent to the following loop:
pos = cell( numel(myCellOfObjects), 1 );
for ii = 1:numel(pos)
pos{ii} = getattr( myCellOfObjects{ii}, 2 );
end
If ever in doubt about cellfun or arrayfun, just write a loop first - they are essentially the same but more concise.
There is a trick to this some are unaware of: you can pass multiple arguments to cellfun like this:
cellfun(#(obj,attr) get(obj,attr), {obj1,obj2},{attr1,attr2},'uni',0)
if you want to get one attribute of the cellarray (instead of providing an attribute for every object in the cellarray), then you can simply use this
cellfun(#(x) getattr(x,attr),obj,'uni',0)
put into anonymous function for convenience:
get_attr = #(obj,attr) cellfun(#(x) getattr(x,attr),obj,'uni',0)
%use:
get_attr(obj_in_cellarray,'myattribute')
%returns cell array of object attributes
I haven't run any of these functions since you didn't provide any example data / code. Please test and feedback.
I need to pass a part of a structure's name into a function.
Examples of a available structs:
systems.system1.stats.equityCurve.relative.exFee
systems.system1.stats.equityCurve.relative.inFee
systems.system2.stats.equityCurve.relative.exFee
systems.system2.stats.equityCurve.relative.inFee
systems.system1.returns.aggregated.exFee
systems.system1.returns.aggregated.inFee
systems.system2.returns.aggregated.exFee
systems.system2.returns.aggregated.inFee
... This goes on...
Within a function, I loop through the structure as follows:
function mat = test(fNames)
feeString = {'exFee', 'inFee'};
sysNames = {'system1', 'system2'};
for n = 1 : 2
mat{n} = systems.(sysNames{n}).stats.equityCurve.relative.(feeString{n});
end
end
What I like to handle in a flexible way within the loop is the middle part, i.e. the part after systems.(sysNames{n}) and before .(feeString{n}) (compare examples).
I am now looking for a way to pass the middle part as an input argument fNames into the function. The loop should than contain something like
mat{n} = systems.(sysNames{n}).(fName).(feeString{n});
How about using a helper function such as
function rec_stru = recSA(stru, field_names)
if numel(field_names) == 1
rec_stru = stru.(field_names{1});
else
rec_stru = recSA(stru.(field_names{1}), field_names(2:end));
end
This function takes the intermediate field names as a cell array.
This would turn this statement:
mat{n} = systems.(sysNames{n}).stats.equityCurve.relative.(feeString{n});
into
mat{n} = recSA(systems.(sysNames{n}), {'stats', 'equityCurve', 'relative', feeString{n}});
The first part of the cell array could then be passed as an argument to the function.
This is one of those cases where matlab is a bit unhelpful in the documentation. There is a way to use the fieldnames function in matlab to get the list of all the fields and iterate over that using dynamic fields.
systems.system1.stats.equityCurve.relative.exFee='T'
systems.system1.stats.equityCurve.relative.inFee='E'
systems.system2.stats.equityCurve.relative.exFee='S'
systems.system2.stats.equityCurve.relative.inFee='T'
systems.system1.returns.aggregated.exFee='D'
systems.system1.returns.aggregated.inFee='A'
systems.system2.returns.aggregated.exFee='T'
systems.system2.returns.aggregated.inFee='A'
dynamicvariable=fieldnames(systems.system1)
This will return a cell matrix of the field names which you can use to iterate over.
systems.system1.(dynamicvariable{1})
ans =
equityCurve: [1x1 struct]
Ideally you would have your data structure fixed in such a way that you know how many levels of depth are in your data structure.
I need to output .mat files for the below data. I need one file to have cell (1,1) to be Mean_RPM_list1, cell (2,1) to be Mean_RPM_list2 etc. And then I need another file to have cell(1,1) to be Mean_Torque_list1 to have cell(1,1).....and so on.
Can anybody shed any light on this for me?
Also if someone knows how to automate me calling the matrices A and B so I could have A = [Mean_rpm1:Mean_rpmMAX], that would also be very helpful.
TIA for any help.
A = [Mean_rpm1 Mean_rpm2 Mean_rpm3 Mean_rpm4 Mean_rpm5 Mean_rpm6 Mean_rpm7 Mean_rpm8 Mean_rpm9 Mean_rpm10 Mean_rpm11 Mean_rpm12];
B = [Mean_torque1 Mean_torque2 Mean_torque3 Mean_torque4 Mean_torque5 Mean_torque6 Mean_torque7 Mean_torque8 Mean_torque9 Mean_torque10 Mean_torque11 Mean_torque12];
plot(A,B,'*')
for i = 1:num_bins;
bin = first + ((i-1)/10);
eval(sprintf('Mean_RPM_list%0.f = A;',bin*10));
eval(sprintf('Mean_Torque_list%0.f = B;',bin*10));
end
First of all this is really bad idea to create a set of variables with names different by numbers. As you can see it's very difficult to deal with such variables, you always have to use eval (or other related) statements.
It's much easier to create a cell array Mean_rpm and access its elements as Mean_rpm{1}, etc.
If the vectors are numeric and have the same size you can also make a 2D/3D array. Then access as Mean_rpm(:,:,1) etc.
Next, to store a cell array to a mat-file you have to create this array in MATLAB. No options (at least for now) to do it by parts in a loop. (But you can do it for numeric vectors and matrices using matfile object.) So why do you need this intermediate Mean_RPM_list variable? Just do Mean_RPM_list{bin*10} = A in your loop.
For your first question, if you already have those variables you have to use eval in a loop. Something like
A = [];
for k=1:K
eval(sprintf('A{k} = [A, Mean_rpm%d];',k));
end
You can also get names for all similar variables and combine them.
varlist = who('Mean_rpm*');
A = cell(1,numel(varlist);
for k = 1:numel(varlist)
eval('A{k} = varlist{k};');
end
Here is one without loop using CELL2FUN:
A=cellfun(#(x)evalin('base',x),varlist,'UniformOutput',0);
You should avoid having all these individual variables around in the first place. Data types like arrays, cell arrays and structure arrays exist to help you with this. If you want each variable to be associated with a name, you can use a structure array. I've made an example below. Instead of assigning a value to Mean_rpm1 like you are doing now, assign it to meanStruct.Mean_rpm1 then save the entire structure.
% as you generate values for each variable, assign them to the
% appropriate field.
meanStruct.Mean_rpm1 = [10:10];
meanStruct.Mean_rpm2 = [12:15];
meanStruct.Mean_rpm3 = [13:20];
meanStruct.Mean_rpm4 = [14];
meanStruct.Mean_rpm5 = [15:18];
meanStruct.Mean_rpm6 = [16:20];
meanStruct.Mean_rpm7 = [17:22];
meanStruct.Mean_rpm8 = [18:22];
meanStruct.Mean_rpm9 = [19:22];
meanStruct.Mean_rpm10 = [20:22];
meanStruct.Mean_rpm11 = [21:22];
meanStruct.Mean_rpm12 = [22:23];
% save the structure array
save('meanValues.mat','meanStruct')
% load and access the structure array
clear all
load('meanValues.mat')
temp = meanStruct.Mean_rpm3
I have a cell array that is a list of file names. I transposed them because I find that easier to work with. Now I am attempting to go through each line in each cell and remove the lines based on their file extension. Eventually, I want to use this list as file names to import data from. This is how I transpose the list
for i = 1:numel(F);
a = F(1,i);
b{i} = [a{:}'];
end;
The code I am using to try and read the data in each cell keeps giving me the error input must be of type double or string. Any ideas?
for i = 1:numel(b);
for k = 1:numel(b{1,i});
b(cellfun(textscan(b{1,i}(k,1),'%s.lbl',numel(b)),b))=[];
end;
end;
Thanks in advance.
EDIT: This is for MATLAB. Should have been clear on that. Thanks Brian.
EDIT2: whos for F is
Name Size Bytes Class Attributes
b 1x11 13986188 cell
while for a is
Name Size Bytes Class Attributes
a 1x1 118408 cell
From your description I am not certain how your F array looks, but assuming
F = {'file1.ext1', 'file2.ext2', 'file3.ext2', 'file2.ext1'};
you could remove all files ending with .ext2 like this:
F = F(cellfun('isempty', regexpi(F, '\.ext2$')));
regexpi, which operates on each element in the cell array, returns [] for all files not matching the expression. The cellfun call converts the cell array to a logical array with false at positions corresponding to files ending with .ext2and true for all others. The resulting array may be used as a logical index to F that returns the files that should be kept.
You're using cellfun wrong. It's signature is [A1,...,Am] = cellfun(func,C1,...,Cn). It takes a function as first argument, but you're passing it the result of textscan, which is a cell array of the matching strings. The second argument is a cell array as it should be, but it doesn't make sense to call it over and over in a loop. `cellfun´'s job is to write the loop for you when you want to do the same thing to every cell in a cell array.
Instead of parsing the filename yourself with textscan, I suggest you use fileparts
Since you're already looping over the cell array in transpose-step, it might make sense to do the filtering there. It might look something like this:
for i = 1:numel(F);
a = F(1,i);
[~,~,ext] = fileparts(a{:});
if strcmpi(ext, '.lbl')
b{i} = [a{:}'];
end
end;
How can i access the following structure path with dynamic fieldnames:
var = 'refxtree.CaseDefinition.FlowSheetObjects.MaterialStreamObjects{8}.MaterialStreamObjectParams.Pressure.Value.Text';
fields = textscan(var,'%s','Delimiter','.');
refxtree.(fields{:}) does not work because MaterialStreamObjects contains a cell array of which I want to access the 8th cell and then continue down the structure path.
In the end I want to get and set the fieldvalues.
You need to build the appropriate input to subsref, possibly using substruct. Look at the MATLAB help.
You can define an anonymous function to navigate this particular kind of structure of the form top.field1.field2.field3{item}.field4.field5.field6.field7 (as an aside: is it really necessary to have such a complicated structure?).
getField = #(top,fields,item)top.(fields{1}).(fields{2}).(fields{3}){item}.(fields{4}).(fields{5}).(fields{6}).(fields{7})
setField = #(top,fields,item,val)subsasgn(top.(fields{1}).(fields{2}).(fields{3}){item}.(fields{4}).(fields{5}).(fields{6}),struct('type','.','subs',fields{7}),val);
You use the functions by calling
fieldValue = getField(refxtree,fields,8);
setField(refxtree,fields,8,newFieldValue);
Note that fields is required to have seven elements. If you want to generalize the above, you will have to dynamically create the above functions
In this case, it is easier to just use EVAL:
str = 'refxtree.CaseDefinition.FlowSheetObjects.MaterialStreamObjects{8}.MaterialStreamObjectParams.Pressure.Value.Text';
%# get
x = eval(str)
%# set
evalc([str ' = 99']);