Simple arithmetic calculation question

Hey just had an easy question that I cant seem to solve. Basically this is what I want to do, but it isnt working... (I think you get the gist of what Im trying to do by looking at the incorrect code)

 datastr='0201+03158+04424-06291+05555-004556+003275-090965+014850000003100011F39 02+00364+01836-02658+09456+020408+000839-093108+019160000003100011F39 00004CE4'

        data.Q0=str2double(datastr(5:10))/10000;
        data.Qx=str2double(datastr(11:16))/10000;
        data.Qy=str2double(datastr(17:22))/10000;
        data.Qz=str2double(datastr(23:28))/10000;
        data.Tx=str2double(datastr(29:35))/100;
        data.Ty=str2double(datastr(36:42))/100;
        data.Tz=str2double(datastr(43:49))/100;

        data.Q02=str2double(((datastr(75:80))/10000)) - data.Q0;
        data.Qx2=str2double(((datastr(81:86))/10000)) - data.Qx;
        data.Qy2=str2double(((datastr(87:92))/10000)) - data.Qy;
        data.Qz2=str2double(((datastr(93:98))/10000)) - data.Qz;
        data.Tx2=str2double(((datastr(99:105))/100)) - data.Tx;
        data.Ty2=str2double(((datastr(106:112))/100)) - data.Ty;
        data.Tz2=str2double(((datastr(113:119))/100)) - data.Ty;

[Iain]

I can't see your error.

[Jan]

Looking on incorrect code cannot reveal the intention of the code. Please explain "it isn't working" with any details.

[Jan]

Please answer the question for clarification, delete the question, or post the solution. Thanks.

Answer 1

[Guru]

Well the error is pretty obvious. The following lines is using parenthesis incorrectly:

data.Q02=str2double(((datastr(75:80))/10000)) - data.Q0;
data.Qx2=str2double(((datastr(81:86))/10000)) - data.Qx;
data.Qy2=str2double(((datastr(87:92))/10000)) - data.Qy;
data.Qz2=str2double(((datastr(93:98))/10000)) - data.Qz;
data.Tx2=str2double(((datastr(99:105))/100)) - data.Tx;
data.Ty2=str2double(((datastr(106:112))/100)) - data.Ty;
data.Tz2=str2double(((datastr(113:119))/100)) - data.Ty;

You want to place your parenthesis so str2double operates only on the datastr() and not the divide by.

data.Q02=str2double(datastr(75:80))/10000 - data.Q0;
data.Qx2=str2double(datastr(81:86))/10000 - data.Qx;
data.Qy2=str2double(datastr(87:92))/10000 - data.Qy;
data.Qz2=str2double(datastr(93:98))/10000 - data.Qz;
data.Tx2=str2double(datastr(99:105))/100 - data.Tx;
data.Ty2=str2double(datastr(106:112))/100 - data.Ty;
data.Tz2=str2double(datastr(113:119))/100 - data.Ty;

HTH