Interpolation from a table by using two variables

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.

Answer 1

[Walter Roberson]

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

[Furkan KARDIYEN]

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.

[Walter Roberson]

use readmatrix()

[Furkan KARDIYEN]

Thank you sir, it is all done and clear now.

Answer 2

[Torsten]

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)

[Furkan KARDIYEN]

Thank you, this is very straightforward and usefull