I am trying to get some variables and numbers out from an Excel table using Matlab.
The variables below named "diffZ_trial1-4" should be calculated by the difference between two columns (between "start" and "finish"). However I get the error:
Undefined operator '-' for input arguments of type"
'cell'.
And I have read somewhere that it could be related to the fact that I get {} output instead of [] and maybe I need to use cell2mat or convert the output somehow. But I must have done that wrongly, as it did not work!
Question: How can I calculate the difference between two columns below?
clear all, close all
[num,txt,raw] = xlsread('test.xlsx');
start = find(strcmp(raw,'HNO'));
finish = find(strcmp(raw,'End Trial: '));
%%% TIMELINE EACH TRIAL
time_trial1 = raw(start(1):finish(1),8);
time_trial2 = raw(start(2):finish(2),8);
time_trial3 = raw(start(3):finish(3),8);
time_trial4 = raw(start(4):finish(4),8);
%%%MOVEMENT EACH TRIAL
diffZ_trial1 = raw(start(1):finish(1),17)-raw(start(1):finish(1),11);
diffZ_trial2 = raw(start(2):finish(2),17)-raw(start(2):finish(2),11);
diffZ_trial3 = raw(start(3):finish(3),17)-raw(start(3):finish(3),11);
diffZ_trial4 = raw(start(4):finish(4),17)-raw(start(4):finish(4),11);
You are right, raw contains data of all types, including text (http://uk.mathworks.com/help/matlab/ref/xlsread.html#outputarg_raw). You should use num, which is a numeric matrix.
Alternatively, if you have an updated version of Matlab, you can try readtable (https://uk.mathworks.com/help/matlab/ref/readtable.html), which I think is more flexible. It creates a table from an excel file, containing both text and numbers.
Related
so I am trying to read multiple sheets in excel using matlab by this function:
Data_mat=readmatrix('DATA_I.xlsx');
I tried a couple of things using additional info, bu seems not correct.
If you want the output to be a matrix, use that command. On the other hand, if you want to read tables (considering the column name), you can use the readtable command.
I generated a dummy excel file that only contains 2 sheets with some numbers there. If you want to read the matrices, use the readmatrix, or if you want tables, just change that function to readtable. Both functions have the same argument structure.
% Define the file name
FileName = "MatrixesInFile.xlsx";
% Get the sheets in the excel file
Sheets = sheetnames(FileName);
% Generate the variable with the matrices
myMatrices = struct;
% Read the matrices and store it in the struct
for n=1:length(Sheets)
% Get evaluated sheet
eval_sheet = Sheets{n};
% Get the matrix
values = readmatrix(FileName,'Sheet',eval_sheet);
% Create a field in the struct and store the matrix there
myMatrices.(eval_sheet) = values;
end
% Print the variable
myMatrices
trying to out put a dataframe into txt file (for a feed). a few specific columns are getting automatically converted into float instead of int as intented.
how can i specific those columns to use int as dtype?
i tried to output the whole dataframd as string and that did not work.
the columns i would like to specify are named [CID1] and [CID2]
data = pd.read_sql(sql,conn)
data = data.astype(str)
data.to_csv('data_feed_feed.txt', sep ='\t',index=True)
Based on the code you provided, you turn all of your data to strings just before export.
Thus, you either need to turn some cols back to desired type, such as:
data["CID1"] = data["CID1"].astype(int)
or not convert them in the first place.
It is not clear from what you provided why you'd have issues with ints being converted to floats.
this post provides heaps of info:
stackoverflow.com/a/28648923/9249533
I am currently attempting to parse data that is sent from an outside source serially. An example is as such:
DATA|0|4|7x5|1|25|174-24|7x5|1|17|TERW|7x5|1|9|08MN|7x5|1|1|_
This data can come in many different lengths, but the first few pieces are all the same. Each "piece" originally comes in with CRLF after, so I've replaced them with string.gsub(input,"\r\n","|") so that is why my input looks the way it does.
The part I would like to parse is:
4|7x5|1|25|174-24|7x5|1|17|TERW|7x5|1|9|08MN|7x5|1|1|_
The "4" tells me that there will be four lines total to create this file. I'm using this as a means to set the amount of passes in the loop.
The 7x5 is the font height.
The 1 is the xpos.
The 25 is the ypos.
The variable data (172-24 in this case) is the text at these parameters.
As you can see, it should continue to loop this pattern throughout the input string received. Now the "4" can actually be any variable > 0; with each number equaling a set of four variables to capture.
Here is what I have so far. Please excuse the loop variable, start variable, and print commands. I'm using Linux to run this function to try to troubleshoot.
function loop_input(input)
var = tonumber(string.match(val, "DATA|0|(%d*).*"))
loop = string.match(val, "DATA|0|")
start = string.match(val, loop.."(%d*)|.*")
for obj = 1, var do
for i = 1, 4 do
if i == 1 then
i = "font" -- want the first group to be set to font
elseif i == 2 then
i = "xpos" -- want the second group to be set to xpos
elseif i == 3 then
i = "ypos" -- want the third group to be set to ypos
else
i = "txt" -- want the fourth group to be set to text
end
obj = font..xpos..ypos..txt
--print (i)
end
objects = objects..obj -- concatenate newly created obj variables with each pass
end
end
val = "DATA|0|4|7x5|1|25|174-24|7x5|1|17|TERW|7x5|1|9|08MN|7x5|1|1|_"
print(loop_input(val))
Ideally, I want to create a loop that, depending on the var variable, will plug in the captured variables between the pipe deliminators and then I can use them freely as I wish. When trying to troubleshoot with parenthesis around my four variables (like I have above), I receive the full list of four variables four times in a row. Now I'm having difficulty actually cycling through the input string and actually grabbing them out as the loop moves down the data string. I was thinking that using the pipes as a means to delineate variables from one another would help. Am I wrong? If it doesn't matter and I can keep the [/r/n]+ instead of each "|" then I am definitely all for that.
I've searched around and found some threads that I thought would help but I'm not sure if tables or splitting the inputs would be advisable. Like these threads:
Setting a variable in a for loop (with temporary variable) Lua
How do I make a dynamic variable name in Lua?
Most efficient way to parse a file in Lua
I'm fairly new to programming and trying to teach myself. So please excuse my beginner thread. I have both the "Lua Reference Manual" and "Programming in Lua" books in paperback which is how I've tried to mock my function(s) off of. But I'm having a problem making the connection.
I thank you all for any input or guidance you can offer!
Cheers.
Try this:
val = "DATA|0|4|7x5|1|25|174-24|7x5|1|17|TERW|7x5|1|9|08MN|7x5|1|1|_"
val = val .. "|"
data = val:match("DATA|0|%d+|(.*)$")
for fh,xpos,ypos,text in data:gmatch("(.-)|(.-)|(.-)|(.-)|") do
print(fh,xpos,ypos,text)
end
I have a variable that is created by a loop. The variable is large enough and in a complicated enough form that I want to save the variable each time it comes out of the loop with a different name.
PM25 is my variable. But I want to save it as PM25_year in which the year changes based on `str = fname(13:end)'
PM25 = permute(reshape(E',[c,r/nlay,nlay]),[2,1,3]); % Reshape and permute to achieve the right shape. Each face of the 3D should be one day
str = fname(13:end); % The year
% Third dimension is organized so that the data for each site is on a face
save('PM25_str', 'PM25_Daily_US.mat', '-append')
The str would be a year, like 2008. So the variable saved would be PM25_2008, then PM25_2009, etc. as it is created.
Defining new variables based on data isn't considered best practice, but you can store your data more efficiently using a cell array. You can store even a large, complicated variable like your PM25 variable within a single cell. Here's how you could go about doing it:
Place your PM25 data for each year into the cell array C using your loop:
for i = 1:numberOfYears
C{i} = PM25;
end
Resulting in something like this:
C = { PM25_2005, PM25_2006, PM25_2007 };
Now let's say you want to obtain your variable for the year 2006. This is easy (assuming you aren't skipping years). The first year of your data will correspond to position 1, the second year to position 2, etc. So to find the index of the year you want:
minYear = 2005;
yearDesired = 2006;
index = yearDesired - minYear + 1;
PM25_2006 = C{index};
You can do this using eval, but note that it's often not considered good practice. eval may be a security risk, as it allows user input to be executed as code. A better way to do this may be to use a cell array or an array of objects.
That said, I think this will do what you want:
for year = 2008:2014
eval(sprintf('PM25_%d = permute(reshape(E',[c,r/nlay,nlay]),[2,1,3]);',year));
save('PM25_Daily_US.mat',sprintf('PM25_%d',year),'-append');
end
I do not recommend to set variables like this since there is no way to track these variables and completely prevents all kind of error checking that MATLAB does beforehand. This kind of code is handled completely in runtime.
Anyway in case you have a really good reason for doing this I recommend that you use the function assignin for this.
assignin('caller', ['myvar',num2str(1)], 63);
In my code I'm trying to use load with entries from a cell, but it is not working. The portion of my code below produces a 3 dimensional array of strings. The strings represent the paths to file names.
for i = 1:Something
for j = 1:Something Different
for k = 1: Yet Something Something Different
DataPath{j,k,i} = 'F:\blah\blah\blah\fileijk %file changes based on i,j,and k
end
end
end
In the next part of the code I want to use load to open the files using the path names defined in the code above. I do this using the code below.
Dummy = DataPath{l,(k-1)*TSRRange+m};
Data = load(Dummy);
The idea is for Dummy to take the string content out of DataPath so I can use it in load. By doing this I thought that Dummy would be defined as a string and not a cell, but this is not the case. How do I pull the string out of DataPath so I can use it with load? Thanks.
I have to load the data this way because the data is located in multiple folders. I can post more of the code if needed, but it is complex.
Dummy is a cell because you assigned a 3D cell array but are accessing a 2D cell with Dummy = Datapath{1,(k-1)*TSRRange+m}
I don't believe that you can expect to access all cell elements I this way. Instead, use three indices just as you did when creating it.