Unit 3 EGR 115

Scalar

A single number

Row Vector

Rows by columns i.e. 1×4

Brackets [] and commas ,

How to create a row vector

Column Vector

A group of numbers organized vertically i.e 4×1

Semicolon ; and apostrophe ‘

How to create column vector and transpose matrix

Transpose Matrix

Swapping (i,j) for (j,i)

Matrix

Rows by Columns

Hardcoding Arrays

There should be consistent rows or columns i.e 4×3 not 4×2 and 3×1

Size()

Dimensions of an array

How to use Size()

2 outputs (row and column) or 2 inputs (array, 1 for rows or 2 for columns)

Length()

Finds the maximum of rows or columns; whichever is greater

How to use Length()

1 output needed (i.e only include the Matrix)

Sum()

Finds the sum of array elements

Sum(Matrix3,1)

Sum of all rows

Sum(Matrix3,2)

Sum of all columns

Sum(sum(Matrix3,1)

Sum of all elements

min()

Finds the minimum element within an array

min(Matrix3,[],1)

minimum of each row

min(Matrix3,[],2)

minimum of each column

min(min(Matrix3,[],1))

minimum of whole matrix

max()

Finds the maximum of an array

max(Matrix3,[],1)

finds the max of a row

max(Matrix3,[],2)

Finds the max of a column

max(max(Matrix3,[],1))

Finds the max of a matrix

[H_Value, H_Location] = max(Vector)

Return maximum value and location

[L_Value, L_Location = min(Vector)

Return minimum value and location

Matrix Addition

Can hardcode a number to add or add 2 matrices together

C= A + B

A = [1,2,3,4]

B = [5,6,7,8]

Add together to “C”

AddTest = Matrix4 + [1,2]

Add 1 value to Matrix row, 2 values to Matrix column

M_test_2 = Matrix4 .* [1,2]

Elementwise multiplication

Slicing (Element)

A1=A(2,4)

Slicing(Row)

A1=A(:,2)

Slicing(Column)

A1=A(3,:) or A1=A(3,[1:end])

Slicing(Rows and Columns)

A1=A(1:2,1:4)

Augment Arrays

brackets [] and commas , or brackets and semicolons

Arrays Dimnution

G(:,3) = []

A=zeroes(2,3) and B=ones(2,3)

zeroes and ones functions

Traversing Arrays

Moving through an array element by element

Traversing Format (Vector)

One for loop, if statement depends on if conditions need to be met

Traversing Format (Matrix)

2 for loops, if statements dependent on if conditions need to be met

Referencing

Use one for loop inside of another to use 2 different values

plot(x,y,’linespec’)

Plotting

hold on, hold off

2 plots

title(‘titleL’)

Title

xlabel(‘x’)

X axis label

ylabel(‘y’)

Y axis label

ylim[,] and xlim[,]

Axis limits

legend(‘x’,’y’)

Graph legend

y=linspace(x1,x2,n)

Plotting Functions

X1

Starting value of sequence

X2

Ending value of sequence

n

number of points to generate

subplot(row, column, position)

Subplot formula