How can I vectorize this find function?

Question

J J 2018-11-20

0
链接

此问题的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/430877-how-can-i-vectorize-this-find-function

评论： Rena Berman 2020-7-22

for i=1:length(x)
    ind_1 = find(b <x(i), 1, 'last');
    ind_2 = ind_1+1;
    x1 = b(ind_1);
    x2 = b(ind_2);
    y1 = a(ind_1);  
    y2 = a(ind_2); 
    y(i) = (y2-y1)/(x2-x1)*(x(i)-x1) + y1;
end

where b =

0

2.49999993684469e-06

4.99999987368938e-06

7.49999981053406e-06

9.99999974737875e-06

1.24999996842234e-05

1.49999996210681e-05

1.74999986484181e-05

1.99999994947575e-05

2.25000003410969e-05

a = -3.90885305404663

-3.90826201438904

-3.90855741500855

-3.90796637535095

-3.90885305404663

-3.90855741500855

-3.90826201438904

-3.90767097473145

-3.90826201438904

x = 0.500000000000000

1

1.50000000000000

2

2.50000000000000

3

3.50000000000000

4

4.50000000000000

5

3 个评论
显示 1更早的评论隐藏 1更早的评论

Rik 2020-6-26

编辑：Rik 2020-6-26

在 MATLAB Online 中打开

Original question retrieved from Google cache, as posted by doyi joo:

for i=1:length(x)
ind_1 = find(b <x(i), 1, 'last');
ind_2 = ind_1+1;
x1 = b(ind_1);
x2 = b(ind_2);
y1 = a(ind_1);
y2 = a(ind_2);
y(i) = (y2-y1)/(x2-x1)*(x(i)-x1) + y1;
end

where

b =
0
2.49999993684469e-06
4.99999987368938e-06
7.49999981053406e-06
9.99999974737875e-06
1.24999996842234e-05
1.49999996210681e-05
1.74999986484181e-05
1.99999994947575e-05
2.25000003410969e-05
a = -3.90885305404663
-3.90826201438904
-3.90855741500855
-3.90796637535095
-3.90885305404663
-3.90855741500855
-3.90826201438904
-3.90826201438904
-3.90767097473145
-3.90826201438904
x = 0.500000000000000
1
1.50000000000000
2
2.50000000000000
3
3.50000000000000
4
4.50000000000000
5

Rena Berman 2020-7-22

(Answers Dev) Restored edit

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Answer 1

Matt J 2018-11-20

0
链接

此回答的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/430877-how-can-i-vectorize-this-find-function#answer_347914

编辑：Matt J 2018-11-20

在 MATLAB Online 中打开

y=interp1(b,y_acc,x)

2 个评论
显示无隐藏无

Rik 2018-11-20

(reposted as a new question)

Rik 2020-6-26

在 MATLAB Online 中打开

Now deleted comment posted by doyi joo on 20 Nov 2018:

Hey,

Would you be able to help me vectorize this function as well......

%% Find Threshold (y = 2) Points on Rising Edge
for i=1:length(t_pks)-1
ind_y = find(t_raw < t_pks(i+1)& t_raw>t_pks(i));
threshold_pt = find(y_raw(ind_y)<2,1,'last');
x0 = threshold_pt;
y1(i) = y_raw(ind_y(x0));
x1(i) = t_raw(ind_y(x0));
y2(i) = y_raw(ind_y(x0)+1);
x2(i) = t_raw(ind_y(x0)+1);
y(i) = 2;
x(i) = (y(i)-y1(i))*(x2(i)-x1(i))/(y2(i)-y1(i)) + x1(i);
end