Error while making plot of precision -recall curve in this code where m i going wrong?

    function [J,D,rfp,rfn]=segevaluate(o,s)
    % gets label matrix for one tissue in segmented and ground truth 
    % and returns the similarity indices
    % m is  gold truth
    % o is in segmented image
    % rfp false pasitive ratio
    % rfn false negative ratio
    o=o(:);
    s=s(:);
    common=sum(o & s); 
    union=sum(o | s); 
    cm=sum(o); % the number of voxels in m
    co=sum(s); % the number of voxels in o
    J=common/union;
    D=(2*common)/(cm+co);
    rfp=(co-common)/cm;
    rfn=(cm-common)/cm;
    prec=co/sum(co+rfp); recall=co/sum(co+rfn);
  *plot(prec,recall,'-',g,'b--o');*
    fprintf('precision is %f\n',prec);
    fprintf('recall is %f\n',recall);
    fprintf('jacarrdindex value is %f\n',Jaccard);
    fprintf('Dice overlap is %f\n',Dice);
    fprintf('ratio of false positive %f\n',rfp);
    fprintf('ratio of false negative is %f\n',rfn);
getting error
??? Error using ==> plot
Invalid property found.
Object Name :  line
Property Name :  'g'.

Error in ==> segevaluate at 19 plot(prec,recall,'-','g','b--o');

Error in ==> ROC at 5 s=segevaluate(i,is);