Interpolation from a table by using two variables

2022 5 3
2 个回答
回答已采纳
更新时间：2022 5 4
24 次查看（30 天）

0 个投票

Hello i have a slight problem and it is kinda urgent to be honest. I can be considered as a noobie in MATLAB so i ask for forgiveness.
I am working on a rocket trajectory simulation project and i have a dataset acquired from CFD analysis for sea level altitudes of 0,3000,6000 meters and Mach number from 0 to 2.0 by step of 0.1. I created a loop by creating a time array and i can get previous results of Mach and altitude work in the next step, altough my problem is that i want to be able to get value of cd for ie. M=0.25 and h=1230 m in the loop, so far my advances are halted.
Here is the dataset in question, and i am dropping the .csv file if you feel use of.
NaN 0 3000 6000
0 0 0 0
0.1 0.4340 0.45120 0.47110
0.2 0.39540 0.40990 0.42670
0.3 0.37520 0.38850 0.40360
0.4 0.36170 0.37410 0.38820
0.5 0.35150 0.36330 0.37670
0.6 0.34290 0.35420 0.3670
0.7 0.33590 0.34680 0.35920
0.8 0.33090 0.34150 0.35360
0.9 0.32930 0.33980 0.35190
1 0.370 0.38050 0.39240
1.1 0.41110 0.42050 0.43130
1.2 0.39960 0.40830 0.41810
1.3 0.39950 0.40790 0.41750
1.4 0.39080 0.3990 0.40830
1.5 0.3820 0.390 0.39910
1.6 0.36960 0.37730 0.38620
1.7 0.35750 0.36510 0.37380
1.8 0.34610 0.35350 0.3620
1.9 0.3350 0.34230 0.35060
2 0.32440 0.33150 0.33960
So far i had some unsuccesfull attempts by using interp2 as i really could not undersand and use it. Sadly i do not have any meaningful code to show here.

请先登录，再回答此问题。

 采纳的回答

Walter Roberson
Walter Roberson 2022-5-3
Ran in:

1 个投票

Ran in:
data = [
NaN 0 3000 6000
0 0 0 0
0.1 0.4340 0.45120 0.47110
0.2 0.39540 0.40990 0.42670
0.3 0.37520 0.38850 0.40360
0.4 0.36170 0.37410 0.38820];
M = data(2:end,1);
h = data(1,2:end);
cd = data(2:end,2:end);
hq = 1230;
Mq = 0.25;
whos
Name Size Bytes Class Attributes M 5x1 40 double Mq 1x1 8 double cd 5x3 120 double cmdout 1x33 66 char data 6x4 192 double h 1x3 24 double hq 1x1 8 double
cdq = interp2(h, M, cd, hq, Mq)
cdq = 0.3910

3 个评论
显示 1更早的评论 隐藏 1更早的评论

Furkan KARDIYEN
Furkan KARDIYEN 2022-5-3
Thank you so much this helped me a lot and i think i got the logic. I later tried to get the same result by using;
data=readtable('cd_veri.csv'); %I got some success using readtable
As i understand the reason; it caused an error because in the code you provided data is a double. I then imported .csv file directly into workplace by opening it from MATLAB and selected it to save it as a matrix so a double. My aim is to make code look tidy, could you suggest me a method to achieve this so table will not be shown in code still it is not big of a deal of course. I tried load, table2array, transpose functions to no avail.
Also thank you again for the quick reply.
Furkan KARDIYEN
Furkan KARDIYEN 2022-5-4
Thank you sir, it is all done and clear now.

请先登录，再进行评论。

更多回答（1 个）

Torsten
Torsten 2022-5-3

1 个投票

X = 0:3000:6000;
Y = 0:0.1:2;
Z = [0 0 0
0.4340 0.45120 0.47110
0.39540 0.40990 0.42670
0.37520 0.38850 0.40360
0.36170 0.37410 0.38820
0.35150 0.36330 0.37670
0.34290 0.35420 0.3670
0.33590 0.34680 0.35920
0.33090 0.34150 0.35360
0.32930 0.33980 0.35190
0.370 0.38050 0.39240
0.41110 0.42050 0.43130
0.39960 0.40830 0.41810
0.39950 0.40790 0.41750
0.39080 0.3990 0.40830
0.3820 0.390 0.39910
0.36960 0.37730 0.38620
0.35750 0.36510 0.37380
0.34610 0.35350 0.3620
0.3350 0.34230 0.35060
0.32440 0.33150 0.33960];
Xq = 2000;
Yq = 0.55;
Zq = interp2(X,Y,Z,Xq,Yq)

类别

在 帮助中心 和 File Exchange 中查找有关 Tables 的更多信息

产品

版本

R2016b

标签

Community Treasure Hunt

Find the treasures in MATLAB Central and discover how the community can help you!

Start Hunting!

Translated by