nvis is a matrix viewer for matrices of any size. Its aimed towards MATLAB users that need to asses a lot of higher-dimensional data in their daily workflow.
Multidimensional: Visualization works for matrices independent of their dimensionality. While the display is limited to two dimensions at a time, selecting datasets along the remaining dimensions is done via sliders.
Versatile: Supports complex valued data, all numeric datatypes and gpuArrays.
Dynamic: nvis allows navigating through the matrix data, while one dimension is contiuously looped.
Comparative: Two input matrices can be displayed simultaneously.
Interactive: Colormap limits (windowing) can be adjusted by moving the mouse (windowing).
Quantitative: Two regions of interest (ROIs) can be drawn. One for signal (mean value is calculated) and one for noise (standard deviation is calculated).
Lightweight: nvis does not create a memory copy of the inputs in order to reduce RAM load incase of large matrices.
nvis can be called with one
nvis(A)
or two input matrices
nvis(A, B)
B must have the same size as A. Except: A and B can differ in size along one or more dimensions, as long as either A or B are singleton. E.g.
nvis(rand(100, 100, 10, 1), rand(100, 100, 1, 5))
For dimensions where all input matrices are singleton, no slider is shown.
The limits of the colormap can be changed with center and width values. These can also be varied interactively by pressing middle or right mouse button on the canvas and dragging the mouse.
Matrix dimensions can be labelled:
nvis(rand(100, 100, 10), 'dimLabel', {'dx', 'dy', 'time'})
Values along each dimension can be labelled with any string. When providing an empty matrix [], the values are enumerated, e.g. 1:size(..., 1).
nvis(rand(100, 100, 10), 'dimVal', {[],[], 0.1*(1:10)})
For complex data, either the absolute value, phase, real- or imaginary part can be displayed. It is also possible to show the 2D Fourier transform of the currently selected slice.
The shown image/animation can also be saved to file. Either from the GUI, or - without opening the GUI -- from the command line.
nvis(imageMat,'CW',[0.5,1],'Colormap','parula','SaveImage','image.png')
nvis(imageMat,'CW',[0.5,1],'Colormap',parula(32),'fps',60,'SaveVideo','animation.gif')
By default, the matrix is displayed as a square. To set the aspect ratio according to the matrix size, use
nvis(A, 'aspectRatio', 'image')
More instructions are documented under
help nvis