matlab 3.1

Question 1

subplot(m, n, p)

Answer 1

breaks figure window into m by n matrix, p is the graph number

Question 2

histogram function

Answer 2

graphs histogram with input array and number of bins
histogram(x,5)
x array, 5 bins

Question 3

symmetric error bar function

Answer 3

errorbar(x, y, e)
x and y vals, e as error. all inputs must be of same length

Question 4

non symmetric error bars function

Answer 4

errorbar(x, y, d, u)
x and y vals, d as the yderr and u as xerr

Question 5

how to adjust thickness of graph lines

Answer 5

plot(x, y, ‘LineWidth’, 2.0)

Question 6

plot3 function

Answer 6

graphs in three dimensions and takes three inputs:
plot3(x, y, z)

Question 7

meshgrid

Answer 7

takes 2 input vectors and creates two 2d matrices for x and y
Xmatrix is copy of x vector over and over, same for y but in columns

Question 8

[X, Y] = meshgrid(x,y)

Answer 8

x and y are input veectors
X is the output matrix, Y is output matrix

Question 9

how do you get Z with meshgrid?

Answer 9

Z = sin(X) .* cos(Y)

Question 10

surf(x,y,z)

Answer 10

shows on three planes with contour lines

Question 11

contour function

Answer 11

represents 3D surface using 2D contour

Question 12

how can you create animations

Answer 12

with loops

Question 13

linear interpolation

Answer 13

uses existing line to estimate value at certain point based off of known points
ex: interp1(x,y,new_x)

Question 14

cubic spine interpolation

Answer 14

smooths curve, minimizes eror
ex: interp1(x,y, new_x, ‘spline’)

Question 15

least squares fitting

Answer 15

finds best fit for data points based on slope and intersection

Question 16

polyfit function

Answer 16

uses least squares fitting to calculate least squares polynomial and create a curve that fits the graph

Question 17

polyval function

Answer 17

evaluates the polynomial created by polyfit for a given set of values

Question 18

diff function

Answer 18

calculates difference for consecutive elements in an array or matrix