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From: TideMan on 16 Jun 2010 17:40
On Jun 17, 7:26 am, "Sydney Hai" <xueying...(a)gmail.com> wrote:
> Hi all,
>
> I have been troubled with this problem using for loop, hope I can get some help.
>
> I am trying to modify a text file with columns of strings and numeric values.
> Here I am extracting XYZ coordinates from a file and then do calculation with all 64 rows of XYZ and find out the four smallest distances from A(X,Y,Z) to B(X1,Y1,Z1)
>
> i used
> for v=1:64
> fid=fopen('FILE_Si.m');
> C=textscan(fid, '%*s %*s %f %f %f %*[^\n]', 64);
> X=C{1,1}(v);
> Y=C{1,2}(v);
> Z=C{1,3}(v);
> end
> to read the coordinates in the file, X, Y, and Z for all 64 rows of the file.
> first of all, is there a way to save the XYZ values I get in the loop to excel or something so I don't end up with only one value in the end? because each new value overwrites the previous one.
> I tried saving all the variables, but then I wouldn't be able to do calculations with all of those or sort them cuz of the variable names.
>
> Then I thought I could do the calculation in the for loop, so when doing the calculation of the distance of this point with another point (X1,Y1,Z1), i used
> distance=sqrt((X-X1)^2+(Y-Y1)^2+(Z-Z1)^2;
> i wish to have all the distances from the 64 calculations so I can sort them in the end to get the four smallest distance values.
> I did [B, IX]=sort(distance); so once I get the smallest value I'll be able to know the index of the XYZ of that min distance.
> but B only contains one value so the sorting is not working.
>
> One last question is, can I set a condition in for loop, that when the A (X, Y, Z) value is the same as C(X2,Y2,Z2), eliminate that A point in the for loop data and the rest of the calculation?
> I tried, for v=1:64, if v=h(my C point), break, end;
> but it wouldn't work.
>
> any idea how I can solve these problems? It's been troubling me for days, thank you all so much!
>
> Best,
> Sydney

This for loop looks all screwed up to me.
You're opening the same file 64 times and reading all 64 rows each
time, then transferring one row at a time into X, Y and Z.
You don't need a for loop at all:
fid=fopen('FILE_Si.m');
C=textscan(fid, '%*s %*s %f %f %f %*[^\n]', 64);
fclose(fid);
X=C{1};
Y=C{2};
Z=C{3};
From: Sydney Hai on 16 Jun 2010 18:43
TideMan <mulgor(a)gmail.com> wrote in message <2745d84d-e974-49ef-b7f2-b66dfb645f4e(a)j8g2000yqd.googlegroups.com>...
> On Jun 17, 7:26 am, "Sydney Hai" <xueying...(a)gmail.com> wrote:
> > Hi all,
> >
> > I have been troubled with this problem using for loop, hope I can get some help.
> >
> > I am trying to modify a text file with columns of strings and numeric values.
> > Here I am extracting XYZ coordinates from a file and then do calculation with all 64 rows of XYZ and find out the four smallest distances from A(X,Y,Z) to B(X1,Y1,Z1)
> >
> > i used
> > for v=1:64
> > fid=fopen('FILE_Si.m');
> > C=textscan(fid, '%*s %*s %f %f %f %*[^\n]', 64);
> > X=C{1,1}(v);
> > Y=C{1,2}(v);
> > Z=C{1,3}(v);
> > end
> > to read the coordinates in the file, X, Y, and Z for all 64 rows of the file.
> > first of all, is there a way to save the XYZ values I get in the loop to excel or something so I don't end up with only one value in the end? because each new value overwrites the previous one.
> > I tried saving all the variables, but then I wouldn't be able to do calculations with all of those or sort them cuz of the variable names.
> >
> > Then I thought I could do the calculation in the for loop, so when doing the calculation of the distance of this point with another point (X1,Y1,Z1), i used
> > distance=sqrt((X-X1)^2+(Y-Y1)^2+(Z-Z1)^2;
> > i wish to have all the distances from the 64 calculations so I can sort them in the end to get the four smallest distance values.
> > I did [B, IX]=sort(distance); so once I get the smallest value I'll be able to know the index of the XYZ of that min distance.
> > but B only contains one value so the sorting is not working.
> >
> > One last question is, can I set a condition in for loop, that when the A (X, Y, Z) value is the same as C(X2,Y2,Z2), eliminate that A point in the for loop data and the rest of the calculation?
> > I tried, for v=1:64, if v=h(my C point), break, end;
> > but it wouldn't work.
> >
> > any idea how I can solve these problems? It's been troubling me for days, thank you all so much!
> >
> > Best,
> > Sydney
>
> This for loop looks all screwed up to me.
> You're opening the same file 64 times and reading all 64 rows each
> time, then transferring one row at a time into X, Y and Z.
> You don't need a for loop at all:
> fid=fopen('FILE_Si.m');
> C=textscan(fid, '%*s %*s %f %f %f %*[^\n]', 64);
> fclose(fid);
> X=C{1};
> Y=C{2};
> Z=C{3};

Thank you for the tip.
I agree, but the reason I'm using a for loop is to calculate the distance.
C{1}, C{2}, C{3} are columns with 64 rows, so I'm using v=1:64 to pick out specific element X,Y,Z and calculate the distance with another point, my ultimate goal is to find a point amongst these 64 that will result in having the smallest distance with that known point. so I would want to do the calculation 64 times and then sort. I just don't know how to save all the data at once without them being overwritten by one another.
any thought?
From: TideMan on 16 Jun 2010 19:13
On Jun 17, 10:43 am, "Sydney Hai" <xueying...(a)gmail.com> wrote:
> TideMan <mul...(a)gmail.com> wrote in message <2745d84d-e974-49ef-b7f2-b66dfb645...(a)j8g2000yqd.googlegroups.com>...
> > On Jun 17, 7:26 am, "Sydney Hai" <xueying...(a)gmail.com> wrote:
> > > Hi all,
>
> > > I have been troubled with this problem using for loop, hope I can get some help.
>
> > > I am trying to modify a text file with columns of strings and numeric values.
> > > Here I am extracting XYZ coordinates from a file and then do calculation with all 64 rows of XYZ and find out the four smallest distances from A(X,Y,Z) to B(X1,Y1,Z1)
>
> > > i used
> > > for v=1:64
> > > fid=fopen('FILE_Si.m');
> > > C=textscan(fid, '%*s %*s %f %f %f %*[^\n]', 64);
> > > X=C{1,1}(v);
> > > Y=C{1,2}(v);
> > > Z=C{1,3}(v);
> > > end
> > > to read the coordinates in the file, X, Y, and Z for all 64 rows of the file.
> > > first of all, is there a way to save the XYZ values I get in the loop to excel or something so I don't end up with only one value in the end? because each new value overwrites the previous one.
> > > I tried saving all the variables, but then I wouldn't be able to do calculations with all of those or sort them cuz of the variable names.
>
> > > Then I thought I could do the calculation in the for loop, so when doing the calculation of the distance of this point with another point (X1,Y1,Z1), i used
> > > distance=sqrt((X-X1)^2+(Y-Y1)^2+(Z-Z1)^2;
> > > i wish to have all the distances from the 64 calculations so I can sort them in the end to get the four smallest distance values.
> > > I did [B, IX]=sort(distance); so once I get the smallest value I'll be able to know the index of the XYZ of that min distance.
> > > but B only contains one value so the sorting is not working.
>
> > > One last question is, can I set a condition in for loop, that when the A (X, Y, Z) value is the same as C(X2,Y2,Z2), eliminate that A point in the for loop data and the rest of the calculation?
> > > I tried, for v=1:64, if v=h(my C point), break, end;
> > > but it wouldn't work.
>
> > > any idea how I can solve these problems? It's been troubling me for days, thank you all so much!
>
> > > Best,
> > > Sydney
>
> > This for loop looks all screwed up to me.
> > You're opening the same file 64 times and reading all 64 rows each
> > time, then transferring one row at a time into X, Y and Z.
> > You don't need a for loop at all:
> > fid=fopen('FILE_Si.m');
> > C=textscan(fid, '%*s %*s %f %f %f %*[^\n]', 64);
> > fclose(fid);
> > X=C{1};
> > Y=C{2};
> > Z=C{3};
>
> Thank you for the tip.
> I agree, but the reason I'm using a for loop is to calculate the distance..
> C{1}, C{2}, C{3} are columns with 64 rows, so I'm using v=1:64 to pick out specific element X,Y,Z and calculate the distance with another point, my ultimate goal is to find a point amongst these 64 that will result in having the smallest distance with that known point. so I would want to do the calculation 64 times and then sort. I just don't know how to save all the data at once without them being overwritten by one another.
> any thought?

Did you even try the code I posted?
If you can be bothered trying it, you'll find that each of the
variables X, Y, and Z have 64 rows.
To get the distances from another point, (X0,Y0,Z0), just do this:
s=sqrt((X-X0).^2 + (Y-Y0).^2 + (Z-Z0).^2);
Now you can use min to find which point is closest to (X0,Y0,Z0).
From: Sydney Hai on 16 Jun 2010 19:27
TideMan <mulgor(a)gmail.com> wrote in message <c87b461f-b8c2-46b0-8803-b8b88d826d65(a)s6g2000prf.googlegroups.com>...
> On Jun 17, 10:43 am, "Sydney Hai" <xueying...(a)gmail.com> wrote:
> > TideMan <mul...(a)gmail.com> wrote in message <2745d84d-e974-49ef-b7f2-b66dfb645...(a)j8g2000yqd.googlegroups.com>...
> > > On Jun 17, 7:26 am, "Sydney Hai" <xueying...(a)gmail.com> wrote:
> > > > Hi all,
> >
> > > > I have been troubled with this problem using for loop, hope I can get some help.
> >
> > > > I am trying to modify a text file with columns of strings and numeric values.
> > > > Here I am extracting XYZ coordinates from a file and then do calculation with all 64 rows of XYZ and find out the four smallest distances from A(X,Y,Z) to B(X1,Y1,Z1)
> >
> > > > i used
> > > > for v=1:64
> > > > fid=fopen('FILE_Si.m');
> > > > C=textscan(fid, '%*s %*s %f %f %f %*[^\n]', 64);
> > > > X=C{1,1}(v);
> > > > Y=C{1,2}(v);
> > > > Z=C{1,3}(v);
> > > > end
> > > > to read the coordinates in the file, X, Y, and Z for all 64 rows of the file.
> > > > first of all, is there a way to save the XYZ values I get in the loop to excel or something so I don't end up with only one value in the end? because each new value overwrites the previous one.
> > > > I tried saving all the variables, but then I wouldn't be able to do calculations with all of those or sort them cuz of the variable names.
> >
> > > > Then I thought I could do the calculation in the for loop, so when doing the calculation of the distance of this point with another point (X1,Y1,Z1), i used
> > > > distance=sqrt((X-X1)^2+(Y-Y1)^2+(Z-Z1)^2;
> > > > i wish to have all the distances from the 64 calculations so I can sort them in the end to get the four smallest distance values.
> > > > I did [B, IX]=sort(distance); so once I get the smallest value I'll be able to know the index of the XYZ of that min distance.
> > > > but B only contains one value so the sorting is not working.
> >
> > > > One last question is, can I set a condition in for loop, that when the A (X, Y, Z) value is the same as C(X2,Y2,Z2), eliminate that A point in the for loop data and the rest of the calculation?
> > > > I tried, for v=1:64, if v=h(my C point), break, end;
> > > > but it wouldn't work.
> >
> > > > any idea how I can solve these problems? It's been troubling me for days, thank you all so much!
> >
> > > > Best,
> > > > Sydney
> >
> > > This for loop looks all screwed up to me.
> > > You're opening the same file 64 times and reading all 64 rows each
> > > time, then transferring one row at a time into X, Y and Z.
> > > You don't need a for loop at all:
> > > fid=fopen('FILE_Si.m');
> > > C=textscan(fid, '%*s %*s %f %f %f %*[^\n]', 64);
> > > fclose(fid);
> > > X=C{1};
> > > Y=C{2};
> > > Z=C{3};
> >
> > Thank you for the tip.
> > I agree, but the reason I'm using a for loop is to calculate the distance.
> > C{1}, C{2}, C{3} are columns with 64 rows, so I'm using v=1:64 to pick out specific element X,Y,Z and calculate the distance with another point, my ultimate goal is to find a point amongst these 64 that will result in having the smallest distance with that known point. so I would want to do the calculation 64 times and then sort. I just don't know how to save all the data at once without them being overwritten by one another.
> > any thought?
>
> Did you even try the code I posted?
> If you can be bothered trying it, you'll find that each of the
> variables X, Y, and Z have 64 rows.
> To get the distances from another point, (X0,Y0,Z0), just do this:
> s=sqrt((X-X0).^2 + (Y-Y0).^2 + (Z-Z0).^2);
> Now you can use min to find which point is closest to (X0,Y0,Z0).

lol, sry I didn't understand it the first time, I tried and all of them had 64 rows, so I wasnt sure if they can do the calculate just by doing that. thanks a lot for your help, I really appreciate it.
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