I've data in the format of
a{1}(1,1)=1
a{1}(1,2)=3
a{1}(1,3)=0.5
a{1}(2,1)=1
a{1}(2,2)=5
a{1}(3,1)=2
a{1}(3,2)=7
...
Now I'd like to place item 1 & 2 of all rows in this cell into another cell array from an specific index on. How should I do this? for example to place column 1 & 2 of these unknown number of row in the cell array 'b' from index 5 on without repetition I used:
b{1}(1,(5:end + 1)) = unique(a{1}(:,(1:2)))
I'd like the output of cell array 'b{1}' from 5th elements becomes '1 2 3 5 7'.
However, it is false and gives the "Subscripted assignment dimension mismatch." error. I dont know where is the problem. Is my snippet right?
Any help is appreciated
Related
I have a 29736 x 6 table, which is referred to as table_fault_test_data. It has 6 columns, with names wind_direction, wind_speed, air_temperature, air_pressure, density_hubheight and Fault_Condition respectively. What I want to do is to label the data in the Fault_Condition (last table column with either a 1 or a 0 value, depending on the values in the other columns.
I would like to do the following checks (For eg.)
If wind_direction value(column_1) is below 0.0040 and above 359.9940, label 6 th column entry corresponding to the respective row of the table as a 1, else label as 0.
Do this for the entire table. Similarly, do this check for others
like air_temperature, air_pressure and so on. I know that if-else
will be used for these checks. But, I am really confused as to how I
can do this for the whole table and add the corresponding value to
the 6 th column (Maybe using a loop or something).
Any help in this
regard would be highly appreciated. Many Thanks!
EDIT:
Further clarification: I have a 29736 x 6 table named table_fault_test_data . I want to add values to the 6 th column of table based on conditions as below:-
for i = 1:29736 % Iterating over the whole table row by row
if(1st column value <x | 1st column value > y)
% Add 0 to the Corresponding element of 6 th column i.e. table_fault_test_data(i,6)
elseif (2nd column value <x | 2nd column value > y)
% Add 0 to the Corresponding element of 6 th column i.e. table_fault_test_data(i,6)
elseif ... do this for other cases as well
else
% Add 1 to the Corresponding element of 6 th column i.e. table_fault_test_data(i,6)
This is the essence of my requirements. I hope this helps in understanding the question better.
You can use logical indexing, which is supported also for tables (for loops should be avoided, if possible). For example, suppose you want to implement the first condition, and also suppose your x and y are known; also, let us assume your table is called t
logicalIndecesFirstCondition = t{:,1} < x | t{:,2} >y
and then you could refer to the rows which verify this condition using logical indexing (please refer to logical indexing
E.g.:
t{logicalIndecesFirstCondition , 6} = t{logicalIndecesFirstCondition , 6} + 1.0;
This would add 1.0 to the 6th column, for the rows for which the logical condition is true
I want to find the overlap between this 2 cell arrays by comparing them row by row and get the overlapped rows:
ex1={'BRDT','TBP';'php','alm';'BRCA1','TP53'};
ex2={'TBP','HIST1H2BH';'RB1','TK2';'php','alm'};
desire_output={'php','alm'}
I have tried this command and get <2x1 cell>array, but i want <1x2 cell>(whole row) :
a=intersect(ex1,ex2,'stable');
How about using ismember and picking the required row?
ex1={'BRDT','TBP';'php','alm';'BRCA1','TP53'};
ex2={'TBP','HIST1H2BH';'RB1','TK2';'php','alm'};
out = ismember(ex1,ex2) ;
iwant = ex1(all(out,2),:) ;
I have a table 'X' like this:
name value score
joy 3 60
rony 8 50
macheis 20 20
joung 2 80
joy 8 3
joy 90 0
joung 4 78
machies 3 23
joy 7 99
I want to select 2 random rows(with name, value, score) where the name is 'joy'.
I applied something like this:
mnew = datasample(find(X.name=='joy'),2); but it does not work! and gives me the error: Undefined operator '==' for input arguments of type 'cell'.
The rows should be selected randomly (with all columns values) where the name is joy.
Does anyone any other solution of this problem? how can i do it in MATLAB?
You have the right idea, but in order to check for the presence of a string within a cell array of strings, you need to use strcmp, ismember, or another method for comparing a string to a cell array.
You probably also want to specify that you don't want to use replacement when calling datasample so you don't get the same row twice.
subx = X(datasample(find(strcmp(X.name, 'joy')), 2, 'Replace', false),:);
I currently have a 4x3500 cell array. First row is a single number, 2 row is a single string, 3rd and 4th rows are also single numbers.
Ex:
1 1 2 3 3 4 5 5 5 6
hi no ya he ........ % you get the idea
28 34 18 0 3 ......
55 2 4 42 24 .....
I would like to be able to select all columns that have a certain value in the first row. ie if I wanted '1' as the first row value, it would return
1 1
hi no
28 34
55 2
Then I would like to sort based on the 2nd row's string. ie if I wanted to have'hi', it would return:
1
hi
28
55
I have attempted to do:
variable = cellArray{:,find(cellArray{1,:} == 1)}
However I keep getting:
Error using find
Too many input arguments.
or
Error using ==
Too many input arguments.
Any help would be much appreciated! :)
{} indexing will return a comma separated list which will provide multiple outputs. When you pass this to find, it's the same as passing each element of your cell array as a separate input. This is what leads to the error about to many input arguments.
You will want to surround the comma-separated list with [] to create an array or numbers. Also, you don't need find because you can just use logical indexing to grab the columns you want. Additionally, you will want to index using () to grab the relevant rows, again to avoid the comma-separated list.
variable = cellArray(:, [cellArray{1,:}] == 1)
So, presume a matrix like so:
20 2
20 2
30 2
30 1
40 1
40 1
I want to count the number of times 1 occurs for each unique value of column 1. I could do this the long way by [sum(x(1:2,2)==1)] for each value, but I think this would be the perfect use for the UNIQUE function. How could I fix it so that I could get an output like this:
20 0
30 1
40 2
Sorry if the solution seems obvious, my grasp of loops is very poor.
Indeed unique is a good option:
u=unique(x(:,1))
res=arrayfun(#(y)length(x(x(:,1)==y & x(:,2)==1)),u)
Taking apart that last line:
arrayfun(fun,array) applies fun to each element in the array, and puts it in a new array, which it returns.
This function is the function #(y)length(x(x(:,1)==y & x(:,2)==1)) which finds the length of the portion of x where the condition x(:,1)==y & x(:,2)==1) holds (called logical indexing). So for each of the unique elements, it finds the row in X where the first is the unique element, and the second is one.
Try this (as specified in this answer):
>>> [c,~,d] = unique(a(a(:,2)==1))
c =
30
40
d =
1
3
>>> counts = accumarray(d(:),1,[],#sum)
counts =
1
2
>>> res = [c,counts]
Consider you have an array of various integers in 'array'
the tabulate function will sort the unique values and count the occurances.
table = tabulate(array)
look for your unique counts in col 2 of table.