Videowriter, issues with making a video

Hello.

We have some troubles with making a video by using the function VideoWriter. Are we not referring to it correctly? Thanks!

This is our code of the function:

function [AnimationFigure] = SimulationVraag5Function(TDnumber,condition,trialnumber,tibialength,x_knee,y_knee)
% SimulationVraag5Function
% SimulationVraag5Function is a function that will create a plot to visualize
% the pendulum test in a stick figure

% Input arguments
% TDnumber: fill in number of subject, f.e. for TD3 fill in '3'
% condition: fill in '1' if condition is HR, fill in '0' if condition is MR
% trialnumber: fill in number of trial HR/MR, f.e. for MR5 fill in '5'
% tibialength: fill in length of tibia of the subject [in cm]
% x_knee: fill in x-co of the knee (we considered the knee to be a static
% point, the tibia was able to move during the pendulum test) [in cm] (fill in a value that fits in coordinate system of -70 by 70)
% y_knee: fill in y-co of the knee [in cm] (fill in a value that fits in coordinate system of -70 by 70)

% Output arguments
% AnimationFigure: an animation figure of the knee during pendulum test will be made, we considered other segments to be static at a chosen coordinate by us

SimulationVraag5Video = VideoWriter('SimulationVraag5Video.avi');
open(SimulationVraag5Video);

% IMPORT DATA (for this exercise we need IK data)

startpath ='/MATLAB Drive/Assignment_V2/MBEXAMEN/EXAMEN/Data';
Datapath = [startpath '/Data'];
addpath '/MATLAB Drive/Assignment_V2/MBEXAMEN/EXAMEN'

% right/left subjects HR
if condition == 1 % this is the first main loop, condition = 1 stands for HR trials
    
    
    for i = TDnumber % TDnumber was filled in (see function), we will retrieve all the files for specific TDnumber
        dataFolder = [startpath '/TD' num2str(i)];
        dataFile = fullfile(dataFolder, '/IK/HR*.mot');
        pathwayIK_HR = dir(dataFile);
        % loop left subjects HR
        if i == 3 | i == 5 | i == 7 | i == 9 | i == 14 % making a distinction between left/right leg tested subjects, 3/5/7/9/14 are left leg tested
            x_hip = x_knee+30 % since the left leg is tested, we want the x-coordinates of the other joints (hip, shoulder, head) to be positive (will be to the right of knee x-co), so we add a number to the x-co of the knee (to get a relative visual representation)
            y_hip = y_knee+10 % we want the y-coordinates of the other joints (hip, shoulder, head) to be positive (will be above knee y-co)
            x_shoulder = x_knee+35;
            y_shoulder = y_knee+50;
            x_midhead = x_knee+35;
            y_midhead = y_knee+60;
            dataFolder = [startpath '/TD' num2str(i)];
            
            for k = trialnumber % getting the files for the specific HR trial
                % data HR
                
                IKHRdata = importdata(fullfile(pathwayIK_HR(k).folder,pathwayIK_HR(k).name));
                DataHRlinks = IKHRdata.data(:,strcmp('knee_angle_l',IKHRdata.colheaders)); % get the knee_angle_l because left leg testings
                TimeHRlinks = IKHRdata.data(:,strcmp('time',IKHRdata.colheaders));
                kneeangle = IKHRdata.data(:,strcmp('knee_angle_l',IKHRdata.colheaders))
                
                for a = 1:100:length(kneeangle) % we chose steps of 30 between the rows, otherwise the running would take a long time
                    % computing the lengths of the triangle: femur length (length between knee and hip) and length between hip and ankle
                    lengthbetweenkneehip = sqrt(((x_knee-x_hip)^2) + (y_knee-y_hip)^2) % computing distance between two coordinates (co hip and co knee are known)
                    lengthbetweenanklehip = sqrt(tibialength^2 + lengthbetweenkneehip^2 - (2*tibialength * lengthbetweenkneehip * cos(kneeangle(a)))) % law of cosines in a triangle
                    lengthbetweenanklehipsquared = lengthbetweenanklehip^2 % to get rid of the root square on the other side of the equation
                    % vgl1 = (xhip-xankle)^2 + (yhip-yankle)^2 - lengthbetweenanklehipsquared
                    lengthbetweenkneeankle = tibialength % this is known (requested in the funtion as input argument)
                    lengthbetweenkneeanklesquared = tibialength^2 % to get rid of the root square on the other side of the equation
                    % vgl2 = (xknee-xankle)^2 + (yknee-yankle)^2 - lengthbetweenkneeanklesquared
                    
                    syms x_ankle y_ankle
                    E = [((x_hip-x_ankle)^2 + (y_hip-y_ankle)^2 - lengthbetweenanklehipsquared == 0), ((x_knee-x_ankle)^2 + (y_knee-y_ankle)^2 - lengthbetweenkneeanklesquared == 0)]; % two equations are set to zero, two equations so the two unknown variables of x_ankle and y_ankle will be solved
                    S = solve(E,x_ankle,y_ankle)
                    
                    x_ankle = S.x_ankle % there are two possible values for x_ankle
                    y_ankle = S.y_ankle
                    
                    x(1) = x_knee
                    x(2) = x_ankle(1)
                    y(1) = y_knee
                    y(2) = y_ankle(1)
                    
                    
                    xlim([-100 100]); % we chose the width of the plot, do not fill in coordinates that are outside of the plot size
                    ylim([-100 100]);
                    hold on; % hold on so all the plots will be created
                    plot(x_hip,y_hip,'o'); % plot the hip coordinates as a circle
                    plot([x_hip x_knee], [y_hip y_knee]) % plotting a line, we connected the hip co with the knee co
                    % we had to write the x and y co seperatly in a vector
                    text(x_hip,y_hip,'H') % plotting a text next to the circle of the hip coordinate
                    plot(x_shoulder,y_shoulder,'o'); % same procedure as explained above
                    plot([x_shoulder x_hip],[y_shoulder y_hip])
                    text(x_shoulder,y_shoulder,'S')
                    plot([x_shoulder x_midhead],[y_shoulder y_midhead])
                    plot(x_midhead,y_midhead,'o','linewidth',20)
                    text(x(1),y(1),'K')
                    text(x(2),y(2),'E')
                    grid on;
                    plot(x,y) % plotting the line between the requested knee coordinate (see function)
                    % and the ankle angle computed above
                    comet(x,y) % with this function the curve will be followed, so it looks like a drawing
                    frame = getframe(gcf);
                    writeVideo(SimulationVraag5Video,frame);
                end
            end
        else % loop for right subjects HR
            x_hip = x_knee-30 % we subtract a number from the x-knee coordinate so that the joints will be on the left side of the x-knee coordinate (because right leg tested)
            y_hip = y_knee+10
            x_shoulder = x_knee-35;
            y_shoulder = y_knee+50;
            x_midhead = x_knee-35;
            y_midhead = y_knee+60;
            for k = trialnumber
                IKHRdata = importdata(fullfile(pathwayIK_HR(k).folder,pathwayIK_HR(k).name));
                DataHRlinks = IKHRdata.data(:,strcmp('knee_angle_r',IKHRdata.colheaders)); % get the knee_angle_r because right leg testings
                TimeHRlinks = IKHRdata.data(:,strcmp('time',IKHRdata.colheaders));
                kneeangle = IKHRdata.data(:,strcmp('knee_angle_r',IKHRdata.colheaders))
            end
            for a = 1:100:length(kneeangle)
                % computing the lengths of the triangle: femur length (length between knee and hip) and length between hip and ankle
                lengthbetweenkneehip = sqrt(((x_knee-x_hip)^2) + (y_knee-y_hip)^2) % computing distance between two coordinates (co hip and co knee are known)
                lengthbetweenanklehip = sqrt(tibialength^2 + lengthbetweenkneehip^2 - (2*tibialength * lengthbetweenkneehip * cos(kneeangle(a)))) % law of cosines in a triangle
                lengthbetweenanklehipsquared = lengthbetweenanklehip^2 % to get rid of the root square on the other side of the equation
                % vgl1 = (xhip-xankle)^2 + (yhip-yankle)^2 - lengthbetweenanklehipsquared
                lengthbetweenkneeankle = tibialength % this is known (requested in the funtion as input argument)
                lengthbetweenkneeanklesquared = tibialength^2 % to get rid of the root square on the other side of the equation
                % vgl2 = (xknee-xankle)^2 + (yknee-yankle)^2 - lengthbetweenkneeanklesquared
                
                syms x_ankle y_ankle
                E = [((x_hip-x_ankle)^2 + (y_hip-y_ankle)^2 - lengthbetweenanklehipsquared == 0), ((x_knee-x_ankle)^2 + (y_knee-y_ankle)^2 - lengthbetweenkneeanklesquared == 0)]; % two equations are set to zero, two equations so the two unknown variables of x_ankle and y_ankle will be solved
                S = solve(E,x_ankle,y_ankle)
                
                x_ankle = S.x_ankle % there are two possible values for x_ankle
                y_ankle = S.y_ankle
                
                x(1) = x_knee
                x(2) = x_ankle(1)
                y(1) = y_knee
                y(2) = y_ankle(1)
                
                xlim([-100 100]);
                ylim([-100 100]);
                hold on;
                plot(x_hip,y_hip,'o');
                plot([x_hip x_knee], [y_hip y_knee])
                text(x_hip,y_hip,'H')
                plot(x_shoulder,y_shoulder,'o');
                plot([x_shoulder x_hip],[y_shoulder y_hip])
                text(x_shoulder,y_shoulder,'S')
                plot([x_shoulder x_midhead],[y_shoulder y_midhead])
                plot(x_midhead,y_midhead,'o','linewidth',20)
                plot(x,y);
                text(x(1),y(1),'K')
                text(x(2),y(2),'E')
                grid on;
                comet(x,y);
                frame = getframe(gcf);
                writeVideo(SimulationVraag5Video,frame);
            end
        end
    end
end

if condition == 0 % MR trials
    for i = TDnumber
        dataFolder = [startpath '/TD' num2str(i)];
        dataFile = fullfile(dataFolder, '/IK/MR*.mot');
        pathwayIK_MR = dir(dataFile);
        % for loop for left subjects MR trials
        if i == 3 | i == 5 | i == 7 | i == 9 | i == 14
            x_hip = x_knee+30
            y_hip = y_knee+10
            x_shoulder = x_knee+35;
            y_shoulder = y_knee+50;
            x_midhead = x_knee+35;
            y_midhead = y_knee+60;
            for k = trialnumber
                IKMRdata = importdata(fullfile(pathwayIK_MR(k).folder,pathwayIK_MR(k).name));
                DataMRlinks = IKMRdata.data(:,strcmp('knee_angle_l',IKMRdata.colheaders));
                TimeMRlinks = IKMRdata.data(:,strcmp('time',IKMRdata.colheaders));
                kneeangle = IKMRdata.data(:,strcmp('knee_angle_l',IKMRdata.colheaders));
            end
            for a = 1:30:length(kneeangle)
                % computing the lengths of the triangle: femur length (length between knee and hip) and length between hip and ankle
                lengthbetweenkneehip = sqrt(((x_knee-x_hip)^2) + (y_knee-y_hip)^2) % computing distance between two coordinates (co hip and co knee are known)
                lengthbetweenanklehip = sqrt(tibialength^2 + lengthbetweenkneehip^2 - (2*tibialength * lengthbetweenkneehip * cos(kneeangle(a)))) % law of cosines in a triangle
                lengthbetweenanklehipsquared = lengthbetweenanklehip^2 % to get rid of the root square on the other side of the equation
                % vgl1 = (xhip-xankle)^2 + (yhip-yankle)^2 - lengthbetweenanklehipsquared
                lengthbetweenkneeankle = tibialength % this is known (requested in the funtion as input argument)
                lengthbetweenkneeanklesquared = tibialength^2 % to get rid of the root square on the other side of the equation
                % vgl2 = (xknee-xankle)^2 + (yknee-yankle)^2 - lengthbetweenkneeanklesquared
                
                syms x_ankle y_ankle
                E = [((x_hip-x_ankle)^2 + (y_hip-y_ankle)^2 - lengthbetweenanklehipsquared == 0), ((x_knee-x_ankle)^2 + (y_knee-y_ankle)^2 - lengthbetweenkneeanklesquared == 0)]; % two equations are set to zero, two equations so the two unknown variables of x_ankle and y_ankle will be solved
                S = solve(E,x_ankle,y_ankle)
                
                x_ankle = S.x_ankle % there are two possible values for x_ankle
                y_ankle = S.y_ankle
                
                x(1) = x_knee
                x(2) = x_ankle(1)
                y(1) = y_knee
                y(2) = y_ankle(1)
                xlim([-100 100]);
                ylim([-100 100]);
                hold on;
                plott = plot(x,y);
                grid on;
                comet(x,y);
                frame = getframe(gcf);
                writeVideo(SimulationVraag5Video,frame);
            end
        else % right subjects MR trials
            x_hip = x_knee-30
            y_hip = y_knee+10
            x_shoulder = x_knee-35;
            y_shoulder = y_knee+50;
            x_midhead = x_knee-35;
            y_midhead = y_knee+60;
            for k = trialnumber
                IKMRdata = importdata(fullfile(pathwayIK_MR(k).folder,pathwayIK_MR(k).name));
                DataMRlinks = IKMRdata.data(:,strcmp('knee_angle_r',IKMRdata.colheaders));
                TimeMRlinks = IKMRdata.data(:,strcmp('time',IKMRdata.colheaders));
                kneeangle = IKMRdata.data(:,strcmp('knee_angle_r',IKMRdata.colheaders));
            end
            for a = 1:30:length(kneeangle)
                % computing the lengths of the triangle: femur length (length between knee and hip) and length between hip and ankle
                lengthbetweenkneehip = sqrt(((x_knee-x_hip)^2) + (y_knee-y_hip)^2) % computing distance between two coordinates (co hip and co knee are known)
                lengthbetweenanklehip = sqrt(tibialength^2 + lengthbetweenkneehip^2 - (2*tibialength * lengthbetweenkneehip * cos(kneeangle(a)))) % law of cosines in a triangle
                lengthbetweenanklehipsquared = lengthbetweenanklehip^2 % to get rid of the root square on the other side of the equation
                % vgl1 = (xhip-xankle)^2 + (yhip-yankle)^2 - lengthbetweenanklehipsquared
                lengthbetweenkneeankle = tibialength % this is known (requested in the funtion as input argument)
                lengthbetweenkneeanklesquared = tibialength^2 % to get rid of the root square on the other side of the equation
                % vgl2 = (xknee-xankle)^2 + (yknee-yankle)^2 - lengthbetweenkneeanklesquared
                
                syms x_ankle y_ankle
                E = [((x_hip-x_ankle)^2 + (y_hip-y_ankle)^2 - lengthbetweenanklehipsquared == 0), ((x_knee-x_ankle)^2 + (y_knee-y_ankle)^2 - lengthbetweenkneeanklesquared == 0)]; % two equations are set to zero, two equations so the two unknown variables of x_ankle and y_ankle will be solved
                S = solve(E,x_ankle,y_ankle)
                
                x_ankle = S.x_ankle % there are two possible values for x_ankle
                y_ankle = S.y_ankle
                
                x(1) = x_knee
                x(2) = x_ankle(1)
                y(1) = y_knee
                y(2) = y_ankle(1)
                
                xlim([-100 100]);
                ylim([-100 100]);
                hold on;
                plott = plot(x,y);
                grid on;
                comet(x,y);
                frame = getframe(gcf);
                writeVideo(SimulationVraag5Video,frame);
            end
        end
    end
end
close(SimulationVraag5Video);

this is the code of our other script:

SimulationVraag5Function(3,1,1,30,0,0)

[Lissa]

This is the error that we get:

Error using VideoWriter/writeVideo (line 368)
Frame must be 448 by 336

Error in SimulationVraag5Function (line 95)
                    writeVideo(SimulationVraag5Video,frame);

Error in SimulationVraag5 (line 4)
SimulationVraag5Function(3,1,1,30,0,0)

It does makes a file for the video in the current folder.

Answer 1

[Walter Roberson]

https://www.mathworks.com/matlabcentral/answers/329710-how-to-save-a-figure-s-content-as-image#comment_1241428 explains