I've been working on an assignment.
One part of the code I've been working on doesn't work.
There is a file called txt that is a 12x1 cell array with 12 words all in a column, and the code needs to call each name one by one, and do some calculations.
I need the code in line 30 to check if the cell contains the word shmoop, if it does, than it excecutes the code, otherwise it does the other code.
How do I check if the array is the word shmoop!
THANK YOU!
Error using ==
Matrix dimensions must agree.
Error in asd (line 30)
if lanes == 'shmoop';
for c = 2:d
lanes = txt{c,1};
if lanes == 'shmoop';
Monstershit{d,2}=paces;
Monstershit{d,3}=pacez;
Monstershit{d,4}=pacea;
else
Monstershit{d,2}=pacev;
Monstershit{d,3}=peace;
Monstershit{d,4}=pasem;
end
end
Comparing strings with == only works if the dimensions of the two objects are the same. In general, you should use strcmp instead.
Related
I am upgrading my Matlab from 2013b to 2018b and have found out that MathWorks have made quite a few changes to the GUI's.
One problem I am having is getting the value of checkbox. The line below is the code I used to use but now it doesn't work.
if get(handles.check_perf_attr,'Value') == 1
The error message is,
Undefined operator '==' for input arguments of type 'cell'.
So I tried the line below to just get the value that is being returned and then apply some logic.
tValue = get(handles.check_perf_attr,'Value');
However tValue is 2 x 1 cell which in (1, 1) = 0 & (2, 1) = 1. I don't really understand this as surely a checkbox can only be one value true (1) or false (0)?
get returns a cell array with values when applied to an array of handles.
Thus, I think your problem is that handles.check_perf_attr contains two handles, not one.
"Dot notation is a new syntax to access object properties starting in R2014b."
so try
if handles.check_perf_attr.Value == 1
or
tValue = handles.check_perf_attr.Value;
I have many large dataset arrays in my workspace (loaded from a .mat file).
A minimal working example is like this
>> disp(old_ds)
Date firm1 firm2 firm3 firm4
734692 880,0 102,1 32,7 204,2
734695 880,0 102,0 30,9 196,4
734696 880,0 100,0 30,9 200,2
734697 880,0 101,4 30,9 200,2
734698 880,0 100,8 30,9 202,2
where the first row (with the strings) already are headers in the dataset, that is they are already displayed if I run old_ds.Properties.VarNames.
I'm wondering whether there is an easy and/or fast way to make the first column as ObsNames.
As a first approach, I've thought of "exporting" the data matrix (columns 2 to 5, in the example), the vector of dates and then creating a new dataset where the rows have names.
Namely:
>> mat = double(old_ds(:,2:5)); % taking the data, making it a matrix array
>> head = old_ds.Properties.VarNames % saving headers
>> head(1,1) = []; % getting rid of 'Date' from head
>> dates = dataset2cell(old_ds(:,1)); % taking dates as column cell array
>> dates(1) = []; % getting rid of 'Date' from dates
>> new_ds = mat2dataset(mat,'VarNames',head,'ObsNames',dates);
Apart from the fact that the last line returns the following error, ...
Error using setobsnames (line 25)
NEWNAMES must be a nonempty string or a cell array of nonempty strings.
Error in dataset (line 377)
a = setobsnames(a,obsnamesArg);
Error in mat2dataset (line 75)
d = dataset(vars{:},args{:});
...I would have found a solution, then created a function (such to generalize the process for all 22 dataset arrays that I have) and then run the function 22 times (once for each dataset array).
To put things into perspective, each dataset has 7660 rows and a number of columns that ranges from 2 to 1320.
I have no idea about how I could (and if I could) make the dataset directly "eat" the first column as ObsNames.
Can anyone give me a hint?
EDIT: attached a sample file.
Actually it should be quite easy (but the fact that I'm reading your question means that having the same problem, I first googled it before looking up the documentation... ;)
When loading the dataset, use the following command (adjusted to your case of course):
cell_dat{1} = dataset('File', 'YourDataFile.csv', 'Delimiter', ';',...
'ReadObsNames', true);
The 'ReadObsNames' default is false. It takes the header of the first column and saves it in the file or range as the name of the first dimension in A.Properties.DimNames.
(see the Documentation, Section: "Name/value pairs available when using text files or Excel spreadsheets as inputs")
I can't download your sample file, but if you haven't yet solved the problem otherwise, just try the suggested solution and tell if it works. Glad if I could help.
You are almost there, the error message you got is basically saying that Obsname have to be strings. In your case the 'dates' variable is cell array containing doubles. So you just need to convert them to string.
mat = double(piHU(:,2:end)); % taking the data, making it a matrix array
head = piHU.Properties.VarNames % saving headers
head(1) = []; % getting rid of 'Date' from head
dates = dataset2cell(piHU(:,1)); % taking dates as column cell array, here dates are of type double. try typing on the command window class(dates{2}), you can see the output is double.
dates(1) = []; % getting rid of 'Date' from dates
dates_str=cellfun(#(s) num2str(s),dates,'UniformOutput',false); % convert dates to string, now try typing class(dates_str{2}), the output should be char
new_ds = mat2dataset(mat,'VarNames',head,'ObsNames',dates_str); % construct new dataset.
I have a char array A which basically contains a list of files names (each row one file)
(char, 526x26)
val =
0815_5275_UBA_A_1971.txt
0815_5275_UBA_A_1972.txt
0823_6275_UBA_A_1971.txt
0823_6275_UBA_A_1972.txt
0823_6275_UBA_A_1973.txt
...
I also have a variable
B = '0815_5275'
I'd like to select all rows (filenames) that start with B and save them in a new array C.
This should be simple, but somehow I can't make it work.
I've got this:
C = A(A(:,1:9) == B);
but I get the error message:
Error using ==
Matrix dimensions must agree.
I do not know in advance how many rows will match, so I can not pre-define an empty array.
thanks, any help is appreciated!
Try ismember(A(:, 1:numel(B)), B, 'rows') rather to get a logical vector that indexes only the rows you want
and now
A(C,:) to extract the rows
The reason you're getting a dimension mismatch error is because your A(:,1:9) has many rows but B only has one and Matlab does not automatically broadcast like Octave or Python. You could do it using either repmat or bsxfun but in this case ismember is the correct function to choose.
temp(i,1) = rand(1)*(pb(1,num).pos(i,1) - pw(1,num).pos(i,1));
This line gives the following error:
Error using ==> minus
Not enough input arguments.
The following are the definitions of pb and pw.
pw=struct('fitness',[],'pos',{});
pb=struct('fitness',[],'pos',{});
pos is a 2 x 1 array.
When tracking down errors like this, I break the problem up into smaller bits. Especially when the logic isn't readily apparent. Not only does it provide a path that can be used to step through your function using the debugger, but it also makes it more readable.
I've taken liberty with the intermediate variable names.
thisPb = pb(1,num);
thisPw = pw(1,num);
initialPos= pw.pos(i,1);
finalPos = pb.pos(i,1);
whos initialPos finalPos
temp(i,1) = rand(1) * (finalPos - initialPos);
The line with whos will print out the values. Make sure that finalPos and initialPos are both numbers.
One way that you can get this error is when num is an empty matrix.
The expression
>> s(x).a
can return a variable number of outputs, depending on the size of x.
If x = [1,2,3] for example, it will return three values (as long as s has at least three elements).
If x = [] on the other hand, then s(x).a will return no outputs, so the expression
>> disp(s(x).a)
will give you a Not enough input arguments error, which is almost certainly what you're seeing. You should check that num is not empty.
Are you sure, that all values are really initialised? Try to check this before your codeline.
disp(pb(1,num).pos(i,1))
disp(pw(1,num).pos(i,1))
temp(i,1) = rand(1)*(pb(1,num).pos(i,1) - pw(1,num).pos(i,1));
the program is working perfectly but when i am changing it to function the follwing error is beeing displayed:
[Parent1index, Parent1Position, alldcel] = Parent1n(TotalnoOfGrids, noOfNodes, Penalties, test)
??? Index exceeds matrix dimensions.
Error in ==> Parent1n at 10
[~,index]=min(alldcel{t});
Because alldcell{t} may not exist for some values of t if the condition to assign values to it in
if Penalties{t}(r)== 0;
alldcel{t}(r)=inf;
end
is never satisfied. Assume for some t that all values of Penalties{t} are different than zero. Then you would never assign inf to alldcell{t}. That means, you are only extending the cell array alldcell when Penalties{t} is zero for some r. If the condition is never satisfied, alldcell{t} will not exist and asking for it will give you a cell array error.
You should at least initialize it using alldcell = cell(TotalnoOfGrids,1).
Also, comparing for equality to zero using a==0 is not a good idea. You should use abs(a)<tol for some small value tol.
ok with this code the functiion worked:if Penalties{t}(r)> 0;
alldcel {t}(r)=alldcel{t}(r);
else alldcel {t}(r)=inf; but interchanging if statement with else did not