How to multiply 2 columns by a scalar number in MATLAB
3 vues (au cours des 30 derniers jours)
Afficher commentaires plus anciens
Dear All
Hope you all are keeping good.i need 4 columns [X,Y,Z,Volume]in excel and first of all i want to multiply X and Y columns by 0.09 and (Z column contains just one scalar (0.18) value) then want to multiply all these X,Y,Z coordinates to get Volume. the code i am trying is given below. any help is appreciated.
if true
[x, y] = find(handles.maskedImage ~= 0);
% here x and y are created in excel by code line.to calculate the volume. first multiply 0.09 by both columns to get X and Y.
X=times(0.09,x);
Y=times(0.09,y);
Z = repmat(0.18,[length(x),1]);
[FileName,PathName] = uiputfile('*.xls','Save data to spreadsheet');
Volume=times(X,Y,Z);
Data=[X,Y,Z, Volume];
xlswrite([PathName '/' FileName],Data); end
3 commentaires
Image Analyst
le 19 Sep 2013
Modifié(e) : Image Analyst
le 19 Sep 2013
No it doesn't. Think about what you are doing. Multiplying the x,y coordinates of every pixel in the selected region by the spatial calibration factor does not calculate the volume.
Réponse acceptée
Jan
le 19 Sep 2013
X = 0.09 * x;
Y = 0.09 * y;
Volume = X .* Y * 0.18;
3 commentaires
Jan
le 20 Sep 2013
@Image Analyst: I'm physicist and therefore very free in the choice of the definition of the term "volume", "pixel" and "coordinates". It could be a sound volume for a generalization of acoustic sound waves in a high-dimensional space with a linear metric. Or the coordinates could have been transformed before by a difference of neighboring elements.
But without doubt you are right and for the standard definition of a spatial volume in the Euclidean 3D space this calculations are not correct.
@Muhammad: You have to check the results with known test data, e.g. a line (Volume==0), a sphere and a rotated cube. I focused on avoiding the failing times().
Plus de réponses (0)
Voir également
Catégories
En savoir plus sur Image Processing and Computer Vision dans Help Center et File Exchange
Produits
Community Treasure Hunt
Find the treasures in MATLAB Central and discover how the community can help you!
Start Hunting!