Logical vectors
Download as PPTX, PDF•0 likes•213 views
Logical vectors in MATLAB compare elements of vectors and return a logical vector with the same size where each element indicates whether the comparison is true (1) or false (0). Logical vectors can be used to create discontinuous graphs by multiplying a vector by a logical vector that filters out negative values. They can also avoid division by zero errors by replacing zeros with a small nonzero value like eps. Common logical functions for vectors include any(), which returns 1 if any element is nonzero, and all(), which returns 1 only if all elements are nonzero.
![• Vectors are compared element by element
and the resulting vector is called as Logical
Vector. It is one of the most power concepts in
MATLAB.
• For eg try this :
a=1:5;
b=[0 2 3 5 6];
a==b % no semicolon (Result is :
0 1 1 0 0)](https://image.slidesharecdn.com/logicalvectors-120429132928-phpapp02/85/Logical-vectors-3-320.jpg)
![• Try for the o/p of
x = [ 0 0]
any(x)
all(x)
Returns scalar 1 if all elements of vector x r non
zero!
x=1:5;
all(x)
Try to get info abt all logic functions](https://image.slidesharecdn.com/logicalvectors-120429132928-phpapp02/85/Logical-vectors-11-320.jpg)
Logical vectors
- 1. Logical Vectors and Strings
- 2. • TYPE as it is in Command Line : r=1; Chk result r<=.5 ( Result is 0) and then at last r>=.5 ( Result is 1) Now Enter the Following statement : r = 1:5; r<=3 U get 11100 as statement is true for first 3 elements
- 3. • Vectors are compared element by element and the resulting vector is called as Logical Vector. It is one of the most power concepts in MATLAB. • For eg try this : a=1:5; b=[0 2 3 5 6]; a==b % no semicolon (Result is : 0 1 1 0 0)
- 4. • Applications : Discontinuous Graphs : Type these Statements : x=0:pi/20:3*pi; y=sin(x); y=y .* (y>0); plot(x,y)
- 5. • What was the Funda ??? y>0 returns a logical vector with ones where sin(x) is positive as y>0 means it is checked element by element if it is >0 ; and if it is not then it returns 0. After this we multiply by y to get the graph
- 6. • Avoid division by 0 As one of the element of x is exact zero.
- 7. • Use Logical Vector to replace zero with eps. What is eps? • This MATLAB function returns the difference between 1.0 and the next largest number which can be represented in MATLAB, i.e. approximately 2.2e-16.
- 8. • So you type and get :
- 10. • Logical Functions : x is a vector : Try these statements : x=1:5 any(x) any(x) : returns scalar 1 in ans if any element of x is nonzero.
- 11. • Try for the o/p of x = [ 0 0] any(x) all(x) Returns scalar 1 if all elements of vector x r non zero! x=1:5; all(x) Try to get info abt all logic functions
- 13. • Strings :
- 14. • For Basic i/p o/p of string we have : name = input( 'Enter your surname: ', 's' ); Chk the workspace Now type disp(name)