Question

What are the restrictions in naming variables and script files in Matlab?

What is the difference between the operators * and .*

What is the function of the commands help, who, and logspace?

Consider the Van der Waals Equation of State for modeling the P-V-T behavior of gases.

.

Suppose a= 3, b=4, V=5; R=8.3, T=400. Write a Matlab code to compute p.

Answer 1

The information regarding MATLAB is as follows:

1) Restrictions in naming variables and script files:

- The variable names for which a particular value or equation is to be assigned should never be named after the functions in matlab such as add, det, plot etc

- The variable name will be valid if it starts with a letter and followed by digits, letters and underscores.

- The variable name should be under the limits provided by the MATLAB which can be known by the command: " namelengthmax"

- MATLAB is case sensitive. The variable name x and X have huge difference.

- The script files name should never be named after the keywords in MATLAB. such as det, plot, subplot.

-The script files name should never be named after the function which you defined in your MATLAB code.

2) Difference between the operators * and .*

the operator * is used to perform multiplication in MATLAB

the operator .* is used to perform element wise product of the vectors.

If a=[1,2;3,4;5,6] and b=[1,2,3;4,5,6]

c = a*b

= 9 12 15

19 26 33

29 40 51

d = a.*b

= 1 4

9 16

25 36

3)Functions of the commands:

help= It obtains help generally or for a specific function

who= It displays the cuurent workspace variable names which have been used till date.

logspace= It is used for creating frequency vectors i.e, it provides space for 50 variables.

4)MATLAB CODE FOR VAN DER WAAL:

function F= vander(V)

a=3;

b=4;

V=5;

R=8.3;

T=400;

f= ((R*T)/(V-b))-(a/V^2);

F=[f;V];