What I would like to do is have Calc OpenOffice return the value of the denominator of a cell. I could do this with right or left, but then i'm constrained by the position.
Is there a way for me to find the denominator of a cell irrespective of the amount of digits in that cell?
So say i have three cells, A1, B1, C1. with values 1/3; 13/4; 1/1003, respectively
I want Calc to return 3; 4; 1003 in cells A2,B2,C2. The cells I want to get the values from are formatted as text, so as to preserve their original fraction form. The fractions represent error/total.
Is this possible? And how would I go about doing this?
Thanks a lot!
Since no-one responded and you did not report that you found the answer either:
Fraction data in cell A1:
=LEFT(A1;FIND("/";A1;1)-1) = numerator
=MID(A1;FIND("/";A1;1)+1;9) = denominator
Related
I am trying to remove rows from a matrix based on a condition. I have a 371000x5 double matrix, and a 371000x1 vector of dummies (1 and 0). I want to remove each row from the original matrix, where the value of the vector of dummies is 1.
I have tried the following, but it is taking very long:
for i = 1:size(matrix_num,1)
if missing_matrix(i,1) >=0
matrix_num(i,:) = [];
end
end
My Matlab has been busy for over 30 minutes now, so I am not even sure if the code is right. Is there a more efficient way to do this?
Additionally, I have to do the same action on a cell matrix (categorical data). Should I expect any huge difference from the numerical matrix?
The programmatic way of doing this is:
new_matrix = old_matrix(missing_vector==1,:)
for keeping lines with missing_vector 1
new_matrix = old_matrix(missing_vector==0,:)
for removing lines with missing_vector 1
For educational values, if you want the loop to work, don't do that row by row. Your solution causes the matrix to be copied and re-allocated on every row removed.
So, you would be better off if you calculate the resulting matrix size in advance:
new_matrix = zeros(sum(missing_vector), 5)
and then your iteration would work:
index_new=1
for index_old = 1:size(old_matrix,1)
if missing_vector(index_old) ==0
new_matrix(index_new,:) = old_matrix(index_old,:);
end
end
Try compact MATLAB code
matrix_num(missing_matrix>=0,:)=[]
Note : You must make a vector for missing_matrix variable. If this variable is matrix, you need other form of code .
As I know, you can use it in cell array too.
I have data in a cell array as shown in the variable viewer here:
{[2.13949546690144;56.9515770543056],
[1.98550875192835;50.4110852121618],
...}
I want to split it into two columns with two decimal-point numbers as:
2.13 56.95
1.98 50.41
by removing opening and closing braces and semicolons such as [;]
(to do as like "Text to columns" in Excel).
If your N-element cell array C has 2-by-1 numeric data in each cell, you can easily convert that into an N-by-2 numeric matrix M like so (using the round function to round each element to 2 significant digits):
M = round([C{:}].', 2);
The syntax C{:} creates a comma-separated list of the contents of C, equivalent to C{1}, C{2}, ... C{N}. These are all horizontally concatenated using [ ... ], then the result is transposed using .'.
% let's build a matching example...
c = cell(2,1);
c{1} = [2.13949546690144; 56.9515770543056];
c{2} = [1.98550875192835; 50.4110852121618];
% convert your cell array to a double array...
m = cell2mat(c);
% take the odd rows and place them to the left
% take the even rows and place them to the right
m = [m(1:2:end,:) m(2:2:end,:)];
% round the whole matrix to two decimal digits
m = round(m,2);
Depending on your environment settings, you may still see a lot of trailing zeros after the first two decimal digits... but don't worry, everything is ok (on the precision point of view). If you want to display only the "real" digits of your numbers, use this command:
format short g;
you should use cell2mat
A={2.14,1.99;56.95,50.41};
B=cell2mat(A);
As for the rounding, you can do:
B=round(100*B)/100;
n = 215;
N = 215.01:0.1:250;
p = 0.52;
q = 0.48;
Gamblers = (1 - (q/p)^n)./(1 - (q/p).^N);
plot(Gamblers)
Matlab takes the numerators and denominators as simply 1, filling the array with nothing but that value. How can I correct this?
Your denominator and numerator are very close to 1 but not exactly 1. The plot(Gamblers) confirms this.
By default MATLAB will display numbers with four digits after the decimal place. Your numerator is 0.999999966414861, which with four digits rounds to 1. MATLAB uses double precision numbers so your calculation here is still accurate.
Try double clicking on the Gamblers variable to open the variables window and then double clicking on one of the results. You'll see it change from the default display precision to a much more accurate depiction of your variable.
I have a matrix of 0s, 1s, 2s and 3s.If all the elements in the same row are the same then I want it to display the text 'flush'. For example, I have the matrix
[0,1,0,2,3;
0,0,0,0,0;
3,2,1,3,1;
2,2,2,2,2];
How would I program Matlab to recognise the 2nd and 4th row all have the same number?
A = [0,1,0,2,3; 0,0,0,0,0; 3,2,1,3,1; 2,2,2,2,2]
As it was said before if you only have positive numbers you can use the variance.
n_flush = var(A, [], 2) == 0
However, this will fail for negative numbers for example a row like [-2 -1 1 2].
What I would do is to compare the first column with the rest and flag the rows where all the elements are equal.
n_flush = all(bsxfun(#eq, A(:,1), A(:,2:end)),2)
Now, if you want to display flush every time the rows are equal you can do
for ind = find(n_flush)
fprintf('flush row %i\n', ind)
end
If you need to have the whole thing in a one-liner (which is what many Matlab-geeks try to do), then maybe this here will suit your needs
cellfun(#(x) char((x==0)*sprintf('flush')), num2cell(var(A')'), 'UniformOutput', false)
Edit: nice idea GameOfThrows
Yet another solution by explicitly subtracting the first column from each column via duplicating the first column to other columns of a matching-sized matrix.
identical_rows = ~any(A - kron(ones(1,size(A,2)),A(:,1)),2)
Suppose that we have this code:
a = pi;
b = pi+2;
c = pi*2.2
out = [a b c]
returns:
out =
3.1416 5.1416 6.9115
I want this output (without rounding values to two decimal):
out =
3.14 5.14 6.91
I don't want print these values. I want see them with 2 decimals here:
Use format bank to get 2 decimal displayed. More details about the format function in the documentation.
If you want to change how the variables are displayed in the variable editor, have a look at this page of the documentation.
In case you just want to use the first 2 decimals, you can add this line to your previous code:
out(:) = str2num(sprintf('%6.2f',out(:))); % 2 = number of decimals
This is not a beautiful solution but it truncates your values to the 2nd decimal and stores it erasing the following decimals. You will still have some zeros at the end (till you fill the selected format for your variable editor as explained above).