Density measurment using cumulative plots

I have two plots

plot(a,b)

hold on

plot(c,d)

and now i need do:

Answer 1

[Image Analyst]

Did you try trapz()?

[Zuzana Pániková]

No and thanks for advice

[Zuzana Pániková]

the trapz() does not work.

this is my graph and i need to calculate:

[Image Analyst]

You forgot to attach the data and your code.

Answer 2

[Zuzana Pániková]

a =

0

1

2

3

4

5

6

7

8

9

10

11

12

13

14

15

16

17

18

19

20

21

22

23

b

b =

11

6

10

11

23

53

97

138

168

166

172

166

173

184

187

197

191

166

136

97

62

43

27

21

c

c =

0

1

2

3

4

5

6

7

8

9

10

11

12

13

14

15

16

17

18

19

20

21

22

23

d

d =

28

28

24

25

55

167

224

272

299

311

334

348

341

368

378

398

367

357

297

236

181

131

99

49

Fackov_po

Fackov_po =

0 11

1 6

2 10

3 11

4 23

5 53

6 97

7 138

8 168

9 166

10 172

11 166

12 173

13 184

14 187

15 197

16 191

17 166

18 136

19 97

20 62

21 43

22 27

23 21

trapz(b,Fackov_po)

ans =

-2006 160

It is correct?

[Image Analyst]

I don't know. What are the two mat files and the xlsx file in the zip file? Which is yRed, yBlue, and the x values?

Answer 3

[Zuzana Pániková]

mat files and xlsx file you don't have to notice, I forgot to delete it.

yRed is d

yBlue is b

x values is a and c.it's the same.

I want to calculate the area between b and d.

Answer 4

[Image Analyst]

One way is to simply sum the curves and subtract them.

area = abs(sum(d) - sum(b));

That assumes there are no negative values, the curves don't cross, and treats the values like a bar chart (bars with flat tops). If you want to treat them like quadilaterals (like bars but slanted tops), you can use trapz().

[Zuzana Pániková]

Thank you for everthing