why i am getting "Ambiguous property found while using line" error?

i am trying to draw a line from the accelerometer data.. code is as shown below

    [gx,gy,gz] = readAcc(accelerometer);
     disp(gx);
    line([0 gx],[0 0],'Color','r','LineWidth',2,'Marker','o');

but i am getting error as

    Error using line
    Ambiguous property found.
    Object Name :  line
    Property Name :  ''.

    Error in vector (line 45)
    line([0 gx],[0 0],'Color','r','LineWidth',2,'Marker','o');

what might be the cause and how to resolve this problem? it does not display any property name..

Answer 1

[Walter Roberson]

Try the full

      line('XData', [0 gx], 'YData', [0 0],'Color','r','LineWidth',2,'Marker','o');

[Gowrishankar R]

Thanks for your reply but after trying as you said i am getting error like

    Error using line Value must be numeric
    Error in vector (line 46)
    line('XData', [0 gx], 'YData', [0 0],'Color','r','LineWidth',2,'Marker','o');

which value i need to change

[Walter Roberson]

Is your readAcc code from http://www.mathworks.com/matlabcentral/fileexchange/50359-matlab-tetris-using-accelerometer/content/MatlabTetrisFinalProject%20-%20For%20publication/readAcc.m ?

What is class(gx) ?

It appears to me that your gx is probably a string instead of numeric.

[Gowrishankar R]

ya you are correct, i just modified that code like this

    function [gx,gy,gz] = readAcc(out)
    fprintf(out.s,'R');
         accData1=fscanf(out.s,'%s');
         accData2=fscanf(out.s,'%s');
         accData3=fscanf(out.s,'%s');
         gx=accData1;
         gy=accData2;
         gz=accData3;       
         disp(gx);

and even disp(gx) also not working i guess

[Gowrishankar R]

i verified my code and found that gx ='' when i run readAcc for the first time and for the second time gx is numeric value i.e 1.00.. so what should i do now? how to neglect string which is coming for the first time and consider from the second time?

[Walter Roberson]

You are returning string values, not numeric values. You cannot use string values to plot with, not without converting them to numeric values. Which is what the %u format was for, to convert the string to numeric values.

Why did you change from %u to %s? If your input values have changed from unsigned integer to floating point, use %f not %s

[Gowrishankar R]

That worked...thank you very much..

[Gowrishankar R]

hello Walter Roberson, sorry for asking so many questions again and again, i am encountered another error.. i have 2 .m files readAcc.m and vector.m.. in command window if i type

    [accData1 accData2 accData3]=readAcc(accelerometer)

i get as accData1 = 1.0100

accData2 = -0.0400

accData3 = -0.2700

but when i run vector.m file which has function call as [accData1 accData2 accData3] = readAcc(accelerometer); after that function call if put disp(accData1); i get as 51__ or something like that.. why is like that?