insertion - partial variable assignation or modification
assignation - partial variable assignation
if a is a matrix with dimensions (size(i,'*'),size(j,'*')) , x(i,j)=a returns a new x matrix such as x(int(i(l)),int(j(k)))=a(l,k) for l from 1 to size(i,'*') and k from 1 to size(j,'*') , other initial entries of x are unchanged.
if a is a scalar x(i,j)=a returns a new x matrix such as x(int(i(l)),int(j(k)))=a for l from 1 to size(i,'*') and k from 1 to size(j,'*') , other initial entries of x are unchanged.
If i or j maximum value exceed corresponding x matrix dimension, array x is previously extended to the required dimensions with zeros entries for standard matrices, 0 length character string for string matrices and false values for boolean matrices.
x(i,j)=[] kills rows specified by i if j matches all columns of x or kills columns specified by j if i matches all rows of x . In other cases x(i,j)=[] produce an error.
x(i)=a with a a vector returns a new x matrix such as x(int(i(l)))=a(l) for l from 1 to size(i,'*') , other initial entries of x are unchanged.
x(i)=a with a a scalar returns a new x matrix such as x(int(i(l)))=a for l from 1 to size(i,'*') , other initial entries of x are unchanged.
If i maximum value exceed size(x,1) , x is previously extended to the required dimension with zeros entries for standard matrices, 0 length character string for string matrices and false values for boolean matrices.
matrix a may be a row (respectively a column) vector with dimension size(i,'*') . Resulting x matrix is a row (respectively a column) vector
vector a must be a row vector with dimension size(i,'*')
vector a must be a column vector with dimension size(i,'*')
matrix a must be a row or column vector with dimension size(i,'*') and i maximum value cannot exceed size(x,'*') ,
x(i)=[] kills entries specified by i .
x(i,:)=a is interpreted as x(i,1:size(x,2))=a
x(:,j)=a is interpreted as x(1:size(x,1),j)=a
x(:)=a returns in x the a matrix reshaped according to x dimensions. size(x,'*') must be equal to size(a,'*')
If they are present the ki give the path to a sub-list entry of l data structure. They allow a recursive insertion without intermediate copies. The l(k1)...(kn)(i)=a and l(list(k1,...,kn,i)=a) instructions are interpreted as:
lk1 = l(k1) .. = ..
lkn = lkn-1(kn) lkn(i) = a
lkn-1(kn) = lkn .. = .. l(k1) = lk1
And the l(k1)...(kn)(i,j)=a and l(list(k1,...,kn,list(i,j))=a instructions are interpreted as:
lk1 = l(k1) .. = ..
lkn = lkn-1(kn) lkn(i,j) = a
lkn-1(kn) = lkn .. = .. l(k1)= lk1
i may be :
a real non negative scalar. l(0)=a adds an entry on the "left" of the list l(i)=a sets the i entry of the list l to a . if i>size(l) , l is previously extended with zero length entries (undefined). l(i)=null() suppress the i th list entry.
a polynomial. If i is a polynomial it is interpreted as horner(i,m) where m=size(l) . Even if this feature works for all polynomials, it is recommended to use polynomials in $ for readability.
k1,..kn may be :
real positive scalar.
a polynomial,interpreted as horner(ki,m) where m is the corresponding sub-list size.
a character string associated with a sub-list entry name.
For soft coded matrix types such as rational functions and state space linear systems, x(i) syntax may not be used for vector entry insertion due to confusion with list entry insertion. x(1,j) or x(i,1) syntax must be used.
// MATRIX CASE
a=[1 2 3;4 5 6]
a(1,2)=10
a([1 1],2)=[-1;-2]
a(:,1)=[8;5]
a(1,3:-1:1)=[77 44 99]
a(1)=%s
a(6)=%s+1
a(:)=1:6
a([%t %f],1)=33
a(1:2,$-1)=[2;4]
a($:-1:1,1)=[8;7]
a($)=123
//
x='test'
x([4 5])=['4','5']
//
b=[1/%s,(%s+1)/(%s-1)]
b(1,1)=0
b(1,$)=b(1,$)+1
b(2)=[1 2] // the numerator
// LIST OR TLIST CASE
l=list(1,'qwerw',%s)
l(1)='Changed'
l(0)='Added'
l(6)=['one more';'added']
//
//
dts=list(1,tlist(['x';'a';'b'],10,[2 3]));
dts(2).a=33
dts(2)('b')(1,2)=-100
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