Matlab | those matlab tips you have to know (4)

Hey, hey, hey, here comes the fourth issue ：

1: Convert decimals into fractions and extract numerators and denominators

a=2065/2013 ;
b=split(rats(a),'/')
c=str2num(b{
    1})
d=str2num(b{
    2})

b =
2×1 cell Array
{’ 2065’}
{'2013 ’ }
  \,
c =
2065
  \,
d =
2013

---

2： Cell and array conversion

2.1： Cell rotation value array

Extract all the elements and arrange them in a column :

A={
    1,2,3;4,5,6;7,8,9}
%  Extract all the elements and arrange them in a column 
B1=[A{
    :}]'

A =
3×3 cell Array
{[1]} {[2]} {[3]}
{[4]} {[5]} {[6]}
{[7]} {[8]} {[9]}
  \,
B1 =
1
4
7
2
5
8
3
6
9

Convert a numerical cell array to a numerical array :

A={
    1,2,3;4,5,6;7,8,9};
%  Convert a numerical cell array to a numerical array 
B2=cell2mat(A)
%  The following methods are also acceptable, but the speed is slow 
% B2=reshape([A{
    :}],size(A))

B2 =
1 2 3
4 5 6
7 8 9

String cell to cell numeric array :

C={
    '12','34';'56','78'}
D=reshape(str2num(char(C)),size(C))

C =
2×2 cell Array
{‘12’} {‘34’}
{‘56’} {‘78’}
  \,
D =
12 34
56 78

2.2： Numerical array to cell

Block and transform cells

A=[1,2,3;4,5,6]
%  The line is divided into two pieces, one for each 
%  The column is divided into two parts 1 Row sum 2 That's ok 
B=mat2cell(A,[1,1],[1,2])

A =
1 2 3
4 5 6
  \,
B =
2×2 cell Array
{[1]} {[2 3]}
{[4]} {[5 6]}

No block to cell , The following two methods are equivalent , But obviously, the second method is much simpler ：

A=[1,2,3;4,5,6];

B1=mat2cell(A,ones(1,size(A,1)),ones(1,size(A,2)))

B2=num2cell(A)

B1 =
2×3 cell Array
{[1]} {[2]} {[3]}
{[4]} {[5]} {[6]}
  \,
B2 =
2×3 cell Array
{[1]} {[2]} {[3]}
{[4]} {[5]} {[6]}

---

3： Attribute cell

For this property, you need to set it repeatedly many times :

x=0:.2:4*pi;

hold on
plot(x,sin(x),'-s','LineWidth',2,'MarkerSize',10);
plot(x,sin(0.5.*x),'-^','LineWidth',2,'MarkerSize',10);
plot(x,sin(x).^2,'-o','LineWidth',2,'MarkerSize',10);

Save it in the cell array ：

x=0:.2:4*pi;

hold on
tc={
    'LineWidth',2,'MarkerSize',10};

plot(x,sin(x),'-s',tc{
    :});
plot(x,sin(0.5.*x),'-^',tc{
    :});
plot(x,sin(x).^2,'-o',tc{
    :});

---

4: Delete nan value

One dimensional vector ：

oriData=[1 nan nan 4 nan 5 6]
oriData(isnan(oriData))=[]

oriData =
1 NaN NaN 4 NaN 5 6
  \,
oriData =
1 4 5 6

Delete with nan The line of ：

oriData=[1 2;nan 4;5 6;7 nan]
tData=sum(oriData,2);
oriData(isnan(tData),:)=[]

oriData =
       \,\,\,\,\,\, 1        \,\,\,\,\,\, 2
NaN        \,\,\,\,\,\, 4
       \,\,\,\,\,\, 5        \,\,\,\,\,\, 6
       \,\,\,\,\,\, 7 NaN
  \,
oriData =
1 2
5 6

Of course, if you want to delete nan The column of , Change the code to ：

tData=sum(oriData,1);
oriData(:,isnan(tData))=[]

Of course, draw inferences from one instance , use isinf Function can delete infinite value .

5: Get workspace variables

as everyone knows whos Function can get the current workspace variable ：

And in functions or in app in ,whos The function gets the variables in the current field instead of the workspace variables . have access to evalin The function get is specified as base Variables in the workspace ：

evalin('base','whos')

---

6: Merge multiple fig For the same fig

If we had two fig file , Respectively called 1.fig,2.fig：


Merge into one fig Code ：

fig1=open('1.fig');
fig2=open('2.fig');

figure()
ax1=subplot(2,1,1);
copyobj(fig1.Children.Children,ax1)
delete(fig1)

ax2=subplot(2,1,2);
copyobj(fig2.Children.Children,ax2)
delete(fig2)

---

7: Merge multiple fig To the same axes

Still use some fig file ：

fig1=open('1.fig');
fig2=open('2.fig');

figure()
ax=gca;
copyobj(fig1.Children.Children,ax)
copyobj(fig2.Children.Children,ax)

delete(fig1)
delete(fig2)