For mentioned python code I am getting result as [[0,4,2],[0,4,2]]. Here '2', I am passing dynamically. I want result as [[0,1,2],[0,4,2]], how can I get this?
a = [[0,1,2]]*2
a[1][1] = 4
The issue is in a way you create 2d list a. It holds links to same strings in each row.
Proper way to create it:
a = [[0,1,2] for i in range(2)]
Found here.
Related
I'm relatively new to matlab and would really appreciate any help.
Currently, I have a function (we'll call it readf) that reads in data from a single ascii file into a struct of multiple fields (we'll call it cdata).
names = cellstr(char('A','B','C','D','E','F','G'));
cdata = readf('filestring','dataNames',names);
The function works fine and gives me the correct output of a struct with these field names, with the value of each field name being a cell array of the corresponding data.
My task is to create a for loop that uses this readf function to read in a folder of these ascii files at once. I'm trying to work it so that the for loop creates a struct with an index of the different cdata structs. After trying a few different methods, I am stumped.
This is what I have so far.
files = struct2cell(dir('folderstring')); %creates a cell array of the names of the files withing the folder
for ii=length(files);
cdata(ii) = readf([folderstring,files(1,1:ii),names],'dataName',names);
end;
This is currently giving me the following error.
"Error using horzcat
Dimensions of matrices being concatenated are not consistent."
I am not sure what is wrong. How can I fix this code so i can read in all the data from a folder at once??? Is there a better and more efficient way to do this than making an index to this struct? Perhaps a cell array of different structures or even a structure of nested structures? Thanks!
Change:
for ii=length(files);
cdata(ii) = readf([folderstring,files(1,1:ii),names],'dataName',names);
end;
To:
for ii=1:length(files); % CHECK to make sure length(files) is giving you the right number
cdata(ii) = readf([folderstring,files{ii},names],'dataName',names);
end;
% CHECK files{ii}, with 1,2,3 etc. is giving you the correct file name.
I'm having the following problem which I can't believe there to be a simple solution for. At any rate a google search wasn't succesful.
Suppose I make the following struct
teststruct = struct('field1',{'a','b','c'});
Now I want to add another field called 'field2' filled with 'd', 'e' and 'f'. Basically I want to achieve the result I would have achieved by directly doing.
teststruct2 = struct('field1',{'a','b','c'}, 'field2', {'d','e','f'});
I tried several solutions and the closest I got was
[teststruct(:).field2] = {'d';'e';'f'};
This however puts the entire cell on the right hand side in it's entirety in the objects 'field2' field.
Does anyone know a solution?
Just lift out the instantiation
teststruct.field1 = {'a','b','c'}
teststruct.field2 = {'d','e','f'}
I have a <850x1> cell called x. Each of the individual structures has a 'Tag' name and 'Data' cell with <7168x1 double> data values.
(i.e.
x{1,1}.Tag = 'Channel1', x{1,1}.Data= <7168x1 double>)
So, I want to go through the x cell, identify the structures with 'Channel1' Tag names and pull out that structure's data. Then, combine the data into a cell called Ch1. Here is my approach so far:
n=1:850
if x{n,1}.Tag == 'Channel1'
Ch1{:,n} = x{n,1}.Data;
end
However, this gives an error: Bad cell reference operation.
Any ideas what may be going wrong?
There are 2 issues here. First, your if statement will compare each entry in the string x{n,1}.Tag to each entry in the string 'Channel1'. If the dimensions are not the same, you will get an error. To fix this, you could use the string compare function, strcmp. The other issue is that you are assigning n to all values between 1 and 850 at once. This is the issue that is producing the actual error you are seeing. Instead, you want to step through each of these values one at a time with a for loop. I would suggest trying the following code:
for n=1:850
if strcmp(x{n,1}.Tag, 'Channel1')
Ch1{:,n} = x{n,1}.Data;
end
end
I new to pandas and trying to learn how to work with it. Im having a problem when trying to use an example I saw in one of wes videos and notebooks on my data. I have a csv file that looks like this:
filePath,vp,score
E:\Audio\7168965711_5601_4.wav,Cust_9709495726,-2
E:\Audio\7168965711_5601_4.wav,Cust_9708568031,-80
E:\Audio\7168965711_5601_4.wav,Cust_9702445777,-2
E:\Audio\7168965711_5601_4.wav,Cust_7023544759,-35
E:\Audio\7168965711_5601_4.wav,Cust_9702229339,-77
E:\Audio\7168965711_5601_4.wav,Cust_9513243289,25
E:\Audio\7168965711_5601_4.wav,Cust_2102513187,18
E:\Audio\7168965711_5601_4.wav,Cust_6625625104,-56
E:\Audio\7168965711_5601_4.wav,Cust_6073165338,-40
E:\Audio\7168965711_5601_4.wav,Cust_5105831247,-30
E:\Audio\7168965711_5601_4.wav,Cust_9513082770,-55
E:\Audio\7168965711_5601_4.wav,Cust_5753907026,-79
E:\Audio\7168965711_5601_4.wav,Cust_7403410322,11
E:\Audio\7168965711_5601_4.wav,Cust_4062144116,-70
I loading it to a data frame and the group it by "filePath" and "vp", the code is:
res = df.groupby(['filePath','vp']).size()
res.index
and the output is:
[E:\Audio\7168965711_5601_4.wav Cust_2102513187,
Cust_4062144116, Cust_5105831247,
Cust_5753907026, Cust_6073165338,
Cust_6625625104, Cust_7023544759,
Cust_7403410322, Cust_9513082770,
Cust_9513243289, Cust_9702229339,
Cust_9702445777, Cust_9708568031,
Cust_9709495726]
Now Im trying to approach the index like a dict, as i saw in examples, but when im doing
res['Cust_4062144116']
I get an error:
KeyError: 'Cust_4062144116'
I do succeed to get a result when im putting the filepath, but as i understand and saw in previouse examples i should be able to use the vp keys as well, isnt is so?
Sorry if its a trivial one, i just cant understand why it is working in one example but not in the other.
Rutger you are not correct. It is possible to "partial" index a multiIndex series. I simply did it the wrong way.
The index first level is the file name (e.g. E:\Audio\7168965711_5601_4.wav above) and the second level is vp. Meaning, for each file name i have multiple vps.
Now, this is correct:
res['E:\Audio\7168965711_5601_4.wav]
and will return:
Cust_2102513187 2
Cust_4062144116 8
....
but trying to index by the inner index (the Cust_ indexes) will fail.
You groupby two columns and therefore get a MultiIndex in return. This means you also have to slice using those to columns, not with a single index value.
Your .size() on the groupby object converts it into a Series. If you force it in a DataFrame you can use the .xs method to slice a single level:
res = pd.DataFrame(df.groupby(['filePath','vp']).size())
res.xs('Cust_4062144116', level=1)
That works. If you want to keep it as a series, boolean indexing can help, something like:
res[res.index.get_level_values(1) == 'Cust_4062144116']
The last option is a bit less readable, but sometimes also more flexibile, you could test for multiple values at once for example:
res[res.index.get_level_values(1).isin(['Cust_4062144116', 'Cust_6073165338'])]
I've research this topic extensibly and I'm asking as a last resort before assuming that there is no wildcard for what I want to do.
I need to pull up all the text input elements from the document and add it to an array. However, I only want to add the input elements that have an id.
I know you can use the \S* wildcard when using an id selector such as $(#\S*), however I can't use this because I need to filter the results by text type only as well, so I searching by attribute.
I currently have this:
values_inputs = $("input[type='text'][id^='a']");
This works how I want it to but it brings back only the text input elements that start with an 'a'. I want to get all the text input elements with an 'id' of anything.
I can't use:
values_inputs = $("input[type='text'][id^='']"); //or
values_inputs = $("input[type='text'][id^='*']"); //or
values_inputs = $("input[type='text'][id^='\\S*']"); //or
values_inputs = $("input[type='text'][id^=\\S*]");
//I either get no values returned or a syntax error for these
I guess I'm just looking for the equivalent of * in SQL for JQuery attribute selectors.
Is there no such thing, or am I just approaching this problem the wrong way?
Actually, it's quite simple:
var values_inputs = $("input[type=text][id]");
Your logic is a bit ambiguous. I believe you don't want elements with any id, but rather elements where id does not equal an empty string. Use this.
values_inputs = $("input[type='text']")
.filter(function() {
return this.id != '';
});
Try changing your selector to:
$("input[type='text'][id]")
I figured out another way to use wild cards very simply. This helped me a lot so I thought I'd share it.
You can use attribute wildcards in the selectors in the following way to emulate the use of '*'. Let's say you have dynamically generated form in which elements are created with the same naming convention except for dynamically changing digits representing the index:
id='part_x_name' //where x represents a digit
If you want to retrieve only the text input ones that have certain parts of the id name and element type you can do the following:
var inputs = $("input[type='text'][id^='part_'][id$='_name']");
and voila, it will retrieve all the text input elements that have "part_" in the beginning of the id string and "_name" at the end of the string. If you have something like
id='part_x_name_y' // again x and y representing digits
you could do:
var inputs = $("input[type='text'][id^='part_'][id*='_name_']"); //the *= operator means that it will retrieve this part of the string from anywhere where it appears in the string.
Depending on what the names of other id's are it may start to get a little trickier if other element id's have similar naming conventions in your document. You may have to get a little more creative in specifying your wildcards. In most common cases this will be enough to get what you need.