[NFB-Science] using Graphiti and Matlab to examine tactile images of plots

[John]


> Hello,
> 
> I wanted to start a discussion about doing data visualization as a blind person using the Graphiti tactile graphic display from Orbit Research.
> 
> There are multiple modes for configuring Graphiti.  I have largely reviewed images sent to Graphiti via an HDMI cable connected to my Windows computer.
> 
> I have been using Graphiti for about 4 months now.
> 
>  
> 
> I used Graphiti to display a Matlab figure.
> 
> By default the Matlab figure does not open maximized.
> 
> Matlab has a line of code that makes the opened figure display maximized.
> 
> This allows skipping the Windows commands of alt-space x for maximize window.
> 
> The code below contains several lines of an example.
> 
> The line that matters for maximizing a Matlab figure is
> 
> f1.WindowState = 'maximized';
> 
> MathWorks helpfully provided me this command when I contacted them about how to display figures maximized more efficiently.
> 
> I have found that changing the Matlab line width parameter from its default of a to a value of 7 makes a thick line on the monitor that then displays well on the Graphiti.
> 
> In summary the below Matlab code generates a plot of 2 parabolas.
> 
> The generated figure is maximized. The lines of code also save to file a PNG file of the image.
> 
> I review the generated plot on Graphiti connected to my Windows computer via HDMI.
> 
> The Graphiti takes about 5 seconds to draw the contents of an image that is in view.
> 
> The PNG file can be examined at a later time using Windows image viewer.
> 
>  
> 
> Matlab code follows:
> 
> clear
> 
> close all
> 
> format long
> 
> % Example 6
> 
> lineWidthVal = 7;
> 
> inFileBaseName = 'example6';
> 
> ylineVal1 = 64;
> 
> ylineVal2 = 144;
> 
> xlineVal = 0;
> 
> x = -10:10;
> 
> y2 = 2 * x.^2;
> 
> y1 = (x-2).^2;
> 
> f1 = figure(1);
> 
> f1.WindowState = 'maximized';
> 
> hold on
> 
> plot(x, y1, 'b', 'linewidth', lineWidthVal);
> 
> plot(x, y2, 'g', 'linewidth', lineWidthVal);
> 
> yline(ylineVal1, 'LineWidth', lineWidthVal, 'Color', 'green')
> 
> yline(ylineVal2, 'LineWidth', lineWidthVal, 'Color', 'green')
> 
> xline(xlineVal, 'LineWidth', lineWidthVal, 'Color', 'green')
> 
> scatter(4, 50, 'o')
> 
> tempStrPng = sprintf('%s.png', inFileBaseName);
> 
> saveas(f1, tempStrPng);
> 
>  
> 
>  
> 
> very best,
> 
> John Miller
> 
>