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<HTML><HEAD><TITLE>Newmat09 - change dimensions</TITLE></HEAD><BODY><H2>Change dimensions</H2><A HREF="ch_type.html"> next</A> - <A HREF="ch_type.html"> skip</A> - <A HREF="refer.html"> up</A> - <A HREF="index.html"> start</A><P>The following operations change the dimensions of a matrix. The valuesof the elements are lost.<PRE> A.ReSize(nrows,ncols); // for type Matrix or nricMatrix A.ReSize(n); // for all other types, except Band A.ReSize(n,lower,upper); // for BandMatrix A.ReSize(n,lower); // for LowerBandMatrix A.ReSize(n,upper); // for UpperBandMatrix A.ReSize(n,lower); // for SymmetricBandMatrix</PRE>Use <TT>A.CleanUp()</TT> to set the dimensions of <TT>A</TT> to zeroand release all the heap memory.<P>Remember that <TT>ReSize</TT> destroys values.If you want to <TT>ReSize</TT>, butkeep the values in the bit that is left use something like<PRE> ColumnVector V(100); ... // load values V = V.Rows(1,50); // to get first 50 values.</PRE>If you want to extend a matrix or vector use something like<PRE> ColumnVector V(50); ... // load values { V.Release(); ColumnVector X=V; V.ReSize(100); V.Rows(1,50)=X; } // V now length 100</PRE><P><A HREF="ch_type.html"> next</A> - <A HREF="ch_type.html"> skip</A> - <A HREF="refer.html"> up</A> - <A HREF="index.html"> start</A><P></BODY></HTML>⌨️ 快捷键说明
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