Changeset 94b16b in git

Timestamp:

Feb 10, 2009, 12:06:20 PM (14 years ago)

Author:

Hans Schönemann <hannes@…>

Branches:

(u'spielwiese', 'f6c3dc58b0df4bd712574325fe76d0626174ad97')

Children:

ddc52f476994f64e5e45e74617b4caac7a4162bc

Parents:

6623f3f780187952c14ea18c3548ce12c10af980

Message:

*hannes: include surfer


git-svn-id: file:///usr/local/Singular/svn/trunk@11360 2c84dea3-7e68-4137-9b89-c4e89433aadc

File:

• Singular/LIB/surf.lib (modified) (4 diffs)

Singular/LIB/surf.lib

@@ -1 +1 @@
 // last modified 21.07.2005, Oliver Wienand
 ///////////////////////////////////////////////////////////////////////////////
-version="$Id: surf.lib,v 1.29 2008-12-12 17:27:01 Singular Exp $";
+version="$Id: surf.lib,v 1.30 2009-02-10 11:06:20 Singular Exp $";
 category="Visualization";
 info="
@@ -11 +11 @@
  @texinfo
  To use this library requires the program @code{surf} to be installed.
- @code{surf} is only available for Linux PCs and Sun workstations.
  You can download @code{surf} either from
   @uref{http://sourceforge.net/projects/surf}
   or from @uref{ftp://www.mathematik.uni-kl.de/pub/Math/Singular/utils/}.
+ The procedure surfer requires the program @code{surfer} to be installed.
+ You can download @code{surfer} from
+  @uref{http://www.imaginary2008.de/surfer.php}
  @end texinfo
 
@@ -144 +146 @@
 
   "Press q to exit from 'surf'";
-  if ("ppcMac-darwin" != system("uname")) {
+  if ("ppcMac-darwin" != system("uname"))
+  {
      i=system("sh", surf_call);
-  } else {
+  }
+  else
+  {
      surf_call = surf_call + " || " + "singularsurf "
                  + extra_surf_opts + " " + l +" >/dev/null 2>&1";
@@ -191 +196 @@
 
 }
+proc surfer(ideal f)
+"USAGE:   surfer(f);  f poly
+ASSUME: f defines a surface given by one equation
+RETURN: nothing
+NOTE: requires the external program 'surfer' to be installed,
+      to close the graphical interface just close the window of surfer
+EXAMPLE: example surfer; shows an example
+"
+{
+  string l = "/tmp/surf"+string(system("pid"));
+  string err_mes; // string containing error messages
+  def base=basering;
+  intvec v=num_of_vars(I);
+  int i,j,n;
+  for(i=size(v);i>0;i--)
+  {
+    if (v[i]!=0) { n++; }
+  }
+  if (n==0 or n>3)
+  {
+    err_mes="Cannot plot equations with "+string(n)+" variables";
+    ERROR(err_mes);
+  }
+  ring r=0,(x,y,z),dp;
+  short=0;
+  map phi=base,0;
+  j=1;
+  for(i=1;i<=size(v);i++)
+  {
+    if (v[i]!=0)
+    {
+      phi[i]=var(j);
+      j++;
+      if(j==4) break;
+    }
+  }
+  ideal I=simplify(phi(I),2);
+  if (leadcoef(I[1]) <0) { I[1]=-I[1]; }
+  if (ncols(I)==1 and (n==3 or nvars(base)==3)) // surface
+  {
+    write(":w " + l, "surface=",I[1],";");
+  }
+  else
+  {
+    err_mes = "cannot plot " + string(ncols(I)) + " equations in "
+            + string(n) + " variables";
+    ERROR(err_mes);
+  }
+  string surf_call;
+  surf_call ="surfer " + l + " >/dev/null 2>&1";
+
+  "Close window to exit from 'surfer'";
+  i=system("sh", surf_call);
+
+  if (i != 0)
+  {
+    err_mes = "calling `surfer` failed. (the shell return the error code "
+          + string(i) + ")." + newline +
+          "probably the executable `surfer` is not found.";
+    ERROR(err_mes);
+  }
+  i = system("sh", "/bin/rm "+l);
+}
+example
+{ "EXAMPLE:"; echo = 2;
+  ring rr1 = 0,(x,y,z),dp;
+  // Steiner surface
+  ideal J(2) = x^2*y^2+x^2*z^2+y^2*z^2-17*x*y*z;
+  surfer(J(2));
+
+  // --------------------
+  surfer(x*(x2-y2)+z2);
+
+  // E7
+  surfer(x^3-x*y^3+z^2);
+
+  // Whitney umbrella
+  surfer(z^2-x^2*y);
+
+}
 ///////////////////////////////////////////////////////////////////////////////