function t=sci2exp(a,nom,lmax)
// sci2exp - convert a variable to an expression
//%SYNTAX
// t=sci2exp(a [,nam] [,lmax])
//%PARAMETERS
//   a  : matrix of scalar or polynomials
//   nam: character string
//   t  : vector of string, contains the expression definition
//   lmax : maximum line lengh (0 for no line length control)
//%Example
//  a=[1 2;3 4]
//  sci2exp(a,'aa')
//!
// Copyright INRIA
[lhs,rhs]=argn(0)
$ // import global variable $ in sci2exp context for efficiency
select rhs
case 1 then 
  named=%f
  lmax=90
case 2 then
  if type(nom)==1 then
    lmax=nom
    named=%f
  else
    named=%t
    lmax=90
  end
case 3 then
  named=%t
  if type(nom)==1 then
    [lmax,nom]=(nom,lmax)
  end
end
dots='..';
select type(a)
case 1 then
  t=mat2exp(a,lmax)
case 2 then
  t=pol2exp(a,lmax)
case 4 then
  t=log2exp(a,lmax)
case 5 then
  t=sp2exp(a,lmax)
case 6 then
  t=sp2exp(a,lmax)
case 10 then
  t=str2exp(a,lmax)
case 15 then
  t=list2exp(a,lmax)
case 16 then
  t=tlist2exp(a,lmax)
case 17 then
  t=mlist2exp(a,lmax)
case 11 then
  t=func2exp(a,lmax)
  named=%f
else
  error('Variable translation of type '+string(type(a))+' Non implemented')
end,
if named then
  t(1)=nom+' = '+t(1)
end


function t=str2exp(a,lmax) 
[lhs,rhs]=argn(0)
if rhs<2 then lmax=0,end
[m,n]=size(a),
dots='.'+'.'
t=[];
quote=''''

a=strsubst(a,quote,quote+quote)
dquote='""'
a=strsubst(a,dquote,dquote+dquote)
a=quote(ones(a))+a+quote(ones(a))

for i=1:m
  x=emptystr();
  for j=1:n,
    y=a(i,j);
    if y=='''''' then y='emptystr()',end
    if lmax==0|length(x($))+length(y)<lmax then
      if j==1 then
        x=y
      else
        x($)=x($)+','+y,
      end
    else
      if j>1 then 
	x($)=x($)+','+dots;
	x($+1)=y
      else
	x=y
      end
    end
  end
  if i<m then x($)=x($)+';',end
  if lmax>0 then
    t=[t;x]
  else
    t=t+x
  end
end,
if lmax>0&sum(length(t))<lmax then
  t=strcat(t)
end
if m*n>1 then
  t(1)='['+t(1)
  t($)=t($)+']'
end

function t=mat2exp(a,lmax)

[lhs,rhs]=argn(0)
if rhs<2 then lmax=0,end
if size(a,'*')==0 then t='[]',return,end
[m,n]=size(a);
if m<0 then
  t=mat2exp(a+0);
  if t=='1' then
    t='eye()';
  else
    t='('+t+')*eye()';
  end
  return
end
a=string(a);
dots='.'+'.'
t=[];
if n==1 then
  x=strcat(a,';')
  lx=length(x)
  if lmax==0|lx<lmax then
    t=x;
  else
    ind=strindex(x,';');
    k1=1
    l=0
    while %t
      if lx-l<lmax|k1>length(ind) then t=[t;part(x,l+1:lx)],break,end
      k2=k1-1+maxi(find(ind(k1:$)<l+lmax))
      t=[t;part(x,l+1:ind(k2))]
      k1=k2+1
      l=ind(k2)
    end
  end
elseif m==1 then      
  x=strcat(a,',')
  lx=length(x)
  if lmax==0|lx<lmax then
    t=x;
  else
    ind=strindex(x,',');
    k1=1
    l=0
    while %t
      if lx-l<lmax|k1>length(ind) then t=[t;part(x,l+1:lx)],break,end
      k2=k1-1+maxi(find(ind(k1:$)<l+lmax))
      t=[t;part(x,l+1:ind(k2))+dots]
      k1=k2+1
      l=ind(k2)
    end
  end
else
  for i=1:m
    x=strcat(a(i,:),',')
    if i<m then x=x+';',end
    lx=length(x)
    if lmax==0 then
      t=t+x
    elseif lx<lmax then
      t=[t;x]
    else
      ind=strindex(x,',');
      k1=1
      l=0
      while %t
	if lx-l<lmax|k1>length(ind) then t=[t;part(x,l+1:lx)],break,end
	k2=k1-1+maxi(find(ind(k1:$)<l+lmax))
	t=[t;part(x,l+1:ind(k2))+dots]
	k1=k2+1
	l=ind(k2)
      end
    end
  end
end
if m*n>1 then
  t(1)='['+t(1)
  t($)=t($)+']'
end

function t=pol2exp(a,lmax)
$
[lhs,rhs]=argn(0)
if rhs<2 then lmax=0,end

[m,n]=size(a),var=' ';lvar=1
var=varn(a),lvar=length(var);
while part(var,lvar)==' ' then lvar=lvar-1,end
var=part(var,1:lvar);
if m<0 then
  t=pol2exp(a+0)
  t='('+t+')*eye()'
  return
end
t=[];
for i=1:m
  x=emptystr(1)
  for j=1:n,
    v=a(i,j);d=degree(v);
    v=coeff(v);
    k0=1;while (k0<d+1)&(v(k0))==0 then k0=k0+1,end
    y=emptystr(1)
    nul=%t
    for k=k0:(d+1),
      s=string(v(k))
      if s<>'0' then
	nul=%f
	if part(s,1)==' ' then s=part(s,2:length(s)),end
	mnm=emptystr(1)
	if k>0 then 
	  mnm=var
	  if k>2 then 
	    mnm=mnm+'^'+string(k-1),
	  end
	end
	if k>1 then
	  if string(imag(v(k)))<>'0' then s='('+s+')',end
	  if s=='1' then 
	    s=mnm
	  elseif s=='-1' then
	    s='-'+mnm
	  else
	    s=s+'*'+mnm
	  end
	  if k>k0&part(s,1)<>'-' then s='+'+s,end
	end
	ls=length(s)
	if lmax==0|length(y($))+ls <lmax then
	  y($)=y($)+s
	else
	  y($)=y($)+dots
	  y($+1)=s
	end
      end
    end
    if nul then y='0*'+var,end
    [ny,my]=size(y)

    if lmax==0|length(x($))+length(y(1))<lmax then
      if j==1 then
         x=y(1)
      else
         x($)=x($)+','+y(1),
      end
      if ny>1 then x($+1:$+ny-1)=y(2:ny),end
    else
      if length(x($))==0 then
	//added by Andre Hentz (andre@lcmi.ufsc.br) 10-Oct-95
	x($:$+ny-1) = y;
      else
	x($)=x($)+','+dots;
	x($+1:$+ny)=y
      end
    end
  end
  if i<m then x($)=x($)+';',end
  if lmax>0 then
    t=[t;x]
  else
    t=t+x
  end
end,
if lmax>0&sum(length(t))<lmax then
  t=strcat(t)
end
if m*n>1 then
  t(1)='['+t(1)
  t($)=t($)+']'
end

function t=list2exp(l,lmax)
[lhs,rhs]=argn(0)
if rhs<2 then lmax=0,end
dots='.'+'.';
t='list('
n=length(l)
for k=1:n
  lk=l(k)
  sep=',',if k==1 then sep=emptystr(),end
  if type(lk)==15 then
    t1=list2exp(lk,lmax)
  elseif type(lk)==16 then 
    t1=tlist2exp(lk,lmax)
  elseif type(lk)==17 then 
    t1=mlist2exp(lk,lmax) 
  else
    t1=sci2exp(lk,lmax)
  end
  if size(t1,'*')==1&(lmax==0|maxi(length(t1))+length(t($))<lmax) then
    t($)=t($)+sep+t1
  else
    t($)=t($)+sep+dots
    t=[t;t1]
  end
  lk=null()
end
t($)=t($)+')'


function t=tlist2exp(l,lmax)
$;
[lhs,rhs]=argn(0)
if rhs<2 then lmax=0,end
dots='.'+'.';
t='tlist('
n=length(l)
for k=1:n
  lk=l(k)
  sep=',',if k==1 then sep=emptystr(),end
  if type(lk)==15 then
    t1=list2exp(lk,lmax)
  elseif type(lk)==16 then
    t1=tlist2exp(lk,lmax)
  elseif type(lk)==17 then
    t1=mlist2exp(lk,lmax) 
  else
    t1=sci2exp(lk,lmax)
  end
  if size(t1,'*')==1&(lmax==0|maxi(length(t1))+length(t($))<lmax) then
    t($)=t($)+sep+t1
  else
    t($)=t($)+sep+dots
    t=[t;t1]
  end
end
t($)=t($)+')'

function t=mlist2exp(l,lmax)
$;
[lhs,rhs]=argn(0)
if rhs<2 then lmax=0,end
dots='.'+'.';
t='mlist('
n=size(definedfields(l),'*')
for k=1:n
  lk=getfield(k,l)
  sep=',',if k==1 then sep=emptystr(),end
  if type(lk)==15 then
    t1=list2exp(lk,lmax)
  elseif type(lk)==16 then
    t1=tlist2exp(lk,lmax)
  elseif type(lk)==17 then
    t1=mlist2exp(lk,lmax)  
  else
    t1=sci2exp(lk,lmax)
  end
  if size(t1,'*')==1&(lmax==0|maxi(length(t1))+length(t($))<lmax) then
    t($)=t($)+sep+t1
  else
    t($)=t($)+sep+dots
    t=[t;t1]
  end
end
t($)=t($)+')'

function t=log2exp(a,lmax)
$;
[lhs,rhs]=argn(0)
if rhs<2 then lmax=0,end
[m,n]=size(a),
a1=matrix(a,m*n,1)
F='%f'
T='%t'
a=F(ones(m*n,1))
k=find(a1);
if k<>[] then
  a(k)=T(ones(size(k,'*'),1));
end
a=matrix(a,m,n);
dots='.'+'.'
t=[];
for i=1:m
  x=emptystr()
  for j=1:n,
    y=a(i,j);
    if lmax==0|length(x($))+length(y)<lmax then
      if j==1 then
        x=y
      else
        x($)=x($)+','+y,
      end
    else
      x($)=x($)+','+dots;
      x($+1)=y
    end
  end
  if lmax>0 then
    t=[t;x]
  else
    t=t+x
  end
end,
if lmax>0&sum(length(t))<lmax then
  t=strcat(t,';')
end
if m*n>1 then
  t(1)='['+t(1)
  t($)=t($)+']'
end

function t=func2exp(a,lmax)
[lhs,rhs]=argn(0)
if rhs<2 then lmax=0,end
[out,in,text]=string(a)
if out==[] then out=emptystr(),end
text=str2exp(text,lmax)
nt=size(text,'*')
if named then mac=nom,else mac='mac',end
if nt==1 then
  t='deff(''['+strcat(out,',')+']='+mac+'('+strcat(in,',')+')'','+text+')'
else
  text($)=text($)+')'
  semi=';'
  text(1:$-1)=text(1:$-1)+semi(ones(nt-1,1))'
  t=['deff(''['+strcat(out,',')+']='+mac+'('+strcat(in,',')+')'','+text(1)
    text(2:$)]
end

function t=sp2exp(a,lmax)
[lhs,rhs]=argn(0)
dots='..';
if rhs<2 then lmax=0,end
[ij,v,mn]=spget(a)
t=sci2exp(ij,lmax)
v=sci2exp(v,lmax)
mn=sci2exp(mn,lmax)

t(1)='sparse('+t(1)
if lmax==0|length(t($))+length(v(1))+1<lmax then
  t($)=t($)+','+v(1)
  t=[t;v(2:$)]
else
  t($)=t($)+','+dots
  t=[t;v]
end
if lmax==0|length(t($))+length(mn(1))+1<lmax then
  t($)=t($)+','+mn(1)
  t=[t;mn(2:$)]
else
  t($)=t($)+','+dots
  t=[t;mn]
end
t($)=t($)+')'