dnstrio.blogg.se

Vectorize a matrix matlab
Vectorize a matrix matlab





vectorize a matrix matlab
  1. Vectorize a matrix matlab how to#
  2. Vectorize a matrix matlab full#
  3. Vectorize a matrix matlab plus#

Therefore, I have decided to post a series of examples that show how to recognize certain patterns that arise in loops, and how to replace those loops with matrix operations. Whether you write your programs in SAS/IML language, MATLAB, or R, it is essential to know how to convert loops into equivalent vector operations.

vectorize a matrix matlab

Statistical programmers need to know how to vectorize programs. In statistical programming, vectorization is necessary (but rewarding!) because it can dramatically decrease the run time of a program.

Vectorize a matrix matlab full#

However, life is full of difficult but necessary tasks. The programmer who posted the question knew that vectorization would improve the program, but also stated that "vectorization is really difficult." I agree. The process of converting loops into vector or matrix operations is called vectorization. By transforming several nested DO loops into an equivalent matrix operation, I was able to reduce the run time to about one second. The problem involved four nested DO loops and took hours to run. For example, suppose you want toĬalculate the divided differences for a given equation.Last week someone posted an interesting question to the SAS/IML Support Community. The compact notation will let you tell the computer to do lots ofĬalculations using few commands. m > plot ( x, y, 'y', x, y, 'go' ) > plot ( x, y, 'y', x, y, 'go', x, exp ( x + 1 ), 'm-' ) > whos Name Size Bytes Class ans 3 x1 24 double array b 3 x1 24 double array v 3 x1 24 double array x 1 x1001 8008 double array y 1 x1001 8008 double array Grand total is 2011 elements using 16088 bytes See also SEMILOGX, SEMILOGY, LOGLOG, PLOTYY, GRID, CLF, CLC, TITLE, XLABEL, YLABEL, AXIS, AXES, HOLD, COLORDEF, LEGEND, SUBPLOT, STEM. The X, Y pairs, or X, Y, S triples, can be followed by parameter / value pairs to specify additional properties of the lines.

vectorize a matrix matlab

PLOT returns a column vector of handles to LINE objects, one handle per line. For monochrome systems, PLOT cycles over the axes LineStyleOrder property. The default ColorOrder is listed in the table above for color systems where the default is blue for one line, and for multiple lines, to cycle through the first six colors in the table. The PLOT command, if no color is specified, makes automatic use of the colors specified by the axes ColorOrder property. For example, PLOT ( X, Y, 'y-', X, Y, 'go' ) plots the data twice, with a solid yellow line interpolating green circles at the data points. ) combines the plots defined by the ( X, Y, S ) triples, where the X ' s and Y ' s are vectors or matrices and the S ' s are strings.

Vectorize a matrix matlab plus#

^ triangle ( up ) triangle ( right ) p pentagram h hexagram For example, PLOT ( X, Y, 'c+:' ) plots a cyan dotted line with a plus at each data point PLOT ( X, Y, 'bd' ) plots blue diamond at each data point but does not draw any line. dashdot c cyan + plus - dashed m magenta * star y yellow s square k black d diamond v triangle ( down ) point - solid g green o circle : dotted r red x x - mark. Various line types, plot symbols and colors may be obtained with PLOT ( X, Y, S ) where S is a character string made from one element from any or all the following 3 columns : b blue. In all other uses of PLOT, the imaginary part is ignored. If Y is complex, PLOT ( Y ) is equivalent to PLOT ( real ( Y ), imag ( Y )). PLOT ( Y ) plots the columns of Y versus their index. If X is a scalar and Y is a vector, length ( Y ) disconnected points are plotted. If X or Y is a matrix, then the vector is plotted versus the rows or columns of the matrix, whichever line up. PLOT ( X, Y ) plots vector Y versus vector X. > plot ( x, y ) > plot ( x, y, 'rx' ) > help plot PLOT Linear plot. We willĭefine two vectors and add and subtract them: Notation is the same as found in most linear algebra texts. Operations can be defined with little effort.įirst, we will look at simple addition and subtraction of vectors. Shown, they are put together to demonstrate how relatively complex In this tutorial we will first demonstrate simple manipulations suchĪs addition, subtraction, and multiplication. Vectors ( Introduction to Vectors in Matlab) or matrices ( Introduction to Matrices in Matlab). For more information on those topics see our tutorial on either Know how to create vectors and matrices and know how to index into

vectorize a matrix matlab

Here we assume that you know the basics of defining and Matlab is the ease in which you can manipulate your vectors and Matlab makes it easy to create vectors and matrices.







Vectorize a matrix matlab