Define functions in code and edit code?

Question

Bob Meyes 2024-3-26

0
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此问题的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/2099171-define-functions-in-code-and-edit-code

评论： Dyuman Joshi 2024-3-27

Can you define the following 3 vectorized functions in the code: launch_yr_4d(y2d), apogee, and perigee. The code is below:

% Fetch TLE data from the URL
url_recent = 'https://celestrak.org/NORAD/elements/gp.php?GROUP=visual&FORMAT=tle';
line_list = string(splitlines(webread(url_recent)));
% Ensure line_list has a multiple of 3 number of lines for proper reshaping
line_list = line_list(1:floor(numel(line_list)/3)*3);
% Reshape the line list to separate each TLE into its own column
tle_data = reshape(line_list, 3, []);
% Define Constant used in function
earth_mean_radius = 6371; % km
% Define the functions: launch_yr_4d(y2d), apogee(mean_motion, eccentricity), perigee(mean_motion, eccentricity)
launch_yr_4d = @(y2d) (y2d >= 24) .* (1900 + y2d) + (y2d < 24) .* (2000 + y2d);
apogee = @(mean_motion, eccentricity) (8681663.653 ./ mean_motion) .^ (2/3) .* (1 + eccentricity) - earth_mean_radius;
perigee = @(mean_motion, eccentricity) (8681663.653 ./ mean_motion) .^ (2/3) .* (1 - eccentricity) - earth_mean_radius;
% Extract satellite numbers, launch years, eccentricities, and mean motions in batches
satellite_numbers = str2double(extractBetween(tle_data(2,:), 3, 7));
launch_years_2digit = str2double(extractBetween(tle_data(2,:), 10, 11));
launch_years = launch_yr_4d(launch_years_2digit);
eccentricities = str2double(extractBetween(tle_data(3,:), 27, 33)) * 0.0000001;
mean_motions = str2double(extractBetween(tle_data(3,:), 53, 63));
% Compute perigee and apogee heights in batches
hps = perigee(mean_motions, eccentricities);
has = apogee(mean_motions, eccentricities);
% Convert numerical values to strings with formatting
satNumStr = sprintfc('%05d', satellite_numbers);
launchYearStr = sprintfc('%04d', launch_years);
hpStr = sprintfc('%.2f', round(hps, 2));
haStr = sprintfc('%.2f', round(has, 2));
% Concatenate all string parts
outputStrings = strcat(satNumStr, " ", launchYearStr, " ", hpStr, " ", haStr, " ", string(tle_data(1, :)));
% Join and print all strings
fprintf('%s\n', join(outputStrings, newline));
1963 464.88 1287.62 ATLAS CENTAUR 2         
1964 764.58 812.41 THOR AGENA D R/B        
1964 645.03 754.12 SL-3 R/B                
1967 704.49 796.77 SL-8 R/B                
1968 569.05 607.13 SL-8 R/B                
1968 739.89 748.79 OAO 2                   
1969 582.98 3453.08 ISIS 1                  
1970 1044.43 1051.38 SERT 2                  
1970 254.93 257.61 SL-3 R/B                
1971 468.90 519.18 SL-3 R/B                
1971 724.53 746.23 ASTEX 1                 
1971 385.09 1280.28 SL-8 R/B                
1972 195.66 1293.35 COSMOS 482 DESCENT CRAFT
1972 699.85 708.49 OAO 3 (COPERNICUS)      
1972 630.43 680.15 ATLAS CENTAUR R/B       
1975 763.11 785.39 SL-8 R/B                
1977 487.00 501.09 SL-3 R/B                
1978 748.53 750.94 SEASAT 1                
1979 594.02 614.77 SL-14 R/B               
1979 749.28 772.38 SL-8 R/B                
1980 595.68 619.22 SL-14 R/B               
1981 372.52 897.18 SL-8 R/B                
1981 484.17 521.18 SL-3 R/B                
1981 455.96 470.44 METEOR PRIRODA          
1981 524.37 553.48 SL-3 R/B                
1982 516.29 553.02 SL-3 R/B                
1982 538.47 589.85 SL-3 R/B                
1982 510.96 554.82 SL-3 R/B                
1982 394.93 413.20 COSMOS 1408             
1982 604.60 635.19 SL-14 R/B               
1983 480.31 513.57 SL-3 R/B                
1983 463.39 477.43 COSMOS 1455             
1983 491.84 534.10 SL-3 R/B                
1983 456.15 473.14 COSMOS 1500             
1984 526.18 550.09 COSMOS 1536             
1984 378.95 381.93 COSMOS 1544             
1984 608.80 634.91 SL-14 R/B               
1985 761.70 789.65 SL-8 R/B                
1985 431.15 433.84 COSMOS 1626             
1985 802.26 852.03 SL-12 R/B(2)            
1985 606.36 634.73 SL-14 R/B               
1985 837.54 851.83 SL-16 R/B               
1986 606.96 633.52 SL-14 R/B               
1986 488.99 500.73 COSMOS 1743             
1986 605.46 640.77 SL-14 R/B               
1986 609.30 636.84 SL-14 R/B               
1986 1485.82 1503.59 AJISAI (EGS)            
1987 483.59 487.61 COSMOS 1812             
1987 607.21 635.70 SL-14 R/B               
1987 840.70 871.98 COSMOS 1833             
1987 840.14 845.50 SL-16 R/B               
1987 609.88 637.67 SL-14 R/B               
1987 829.72 873.92 COSMOS 1844             
1987 608.71 637.25 SL-14 R/B               
1987 780.12 809.07 COSMOS 1867             
1987 471.52 484.43 COSMOS 1892             
1988 609.24 637.22 SL-14 R/B               
1988 543.23 549.07 COSMOS 1933             
1988 523.98 569.11 SL-3 R/B                
1988 818.54 850.58 SL-16 R/B               
1988 520.19 543.64 COSMOS 1953             
1988 757.40 786.45 SL-8 R/B                
1988 522.78 546.25 COSMOS 1975             
1988 608.97 636.73 SL-14 R/B               
1988 836.31 856.10 SL-16 R/B               
1989 504.62 2373.78 INTERCOSMOS 24          
1989 505.20 2441.25 SL-14 R/B               
1989 685.47 784.29 DELTA 1 R/B             
1990 762.04 776.92 ARIANE 40 R/B           
1990 408.96 704.04 DELTA 2 R/B(1)          
1990 557.03 574.19 COSMOS 2058             
1990 614.20 644.14 SL-14 R/B               
1990 622.92 644.13 SL-14 R/B               
1990 521.91 525.37 HST                     
1990 838.48 861.70 SL-16 R/B               
1990 497.48 664.55 COSMOS 2084             
1990 514.28 649.72 SL-6 R/B(2)             
1990 367.84 1052.41 SL-8 R/B                
1991 964.82 996.23 SL-8 R/B                
1991 571.22 592.26 OKEAN-3                 
1991 580.13 596.84 COSMOS 2151             
1991 621.27 647.49 SL-14 R/B               
1991 747.27 794.35 ERS-1                   
1991 756.78 762.98 ARIANE 40 R/B           
1991 445.71 2855.22 INTERCOSMOS 25          
1992 960.88 1010.99 SL-8 R/B                
1992 965.20 1009.60 SL-8 R/B                
1992 839.24 867.61 COSMOS 2219             
1992 836.19 851.59 SL-16 R/B               
1992 589.54 612.88 COSMOS 2221             
1992 844.12 853.18 SL-16 R/B               
1992 585.69 613.83 COSMOS 2228             
1993 840.61 857.48 SL-16 R/B               
1993 588.21 613.36 COSMOS 2242             
1993 829.08 856.17 SL-16 R/B               
1993 784.88 799.31 ARIANE 40 R/B           
1994 847.07 858.21 COSMOS 2278             
1994 846.03 854.08 SL-16 R/B               
1994 637.86 648.19 SL-16 R/B               
1994 845.90 850.47 SL-16 R/B               
1995 764.04 775.48 ARIANE 40+ R/B          
1995 840.69 856.18 SL-16 R/B               
1996 847.89 868.07 SL-16 R/B               
1997 782.44 785.81 ORBVIEW 2 (SEASTAR)     
1998 806.86 819.58 SL-16 R/B               
1998 841.47 850.77 SL-16 R/B               
1998 421.96 428.47 ISS (ZARYA)             
1999 813.23 865.76 CZ-4B R/B               
1999 640.79 643.45 OKEAN-O                 
1999 625.38 648.18 SL-16 R/B               
1999 497.48 1250.04 DELTA 2 R/B             
1999 622.81 624.20 HELIOS 1B               
1999 700.99 702.05 TERRA                   
2000 834.96 859.78 SL-16 R/B               
2000 538.85 601.64 TITAN 4B R/B            
2002 769.52 771.49 ENVISAT                 
2002 789.55 808.10 IDEFIX & ARIANE 42P R/B 
2002 702.18 704.76 AQUA                    
2002 816.18 887.53 CZ-4B R/B               
2002 804.39 805.04 MIDORI II (ADEOS-II)    
2002 738.05 841.67 H-2A R/B                
2003 686.87 755.02 CZ-4B R/B               
2004 477.85 525.92 CZ-2C R/B               
2004 848.71 854.31 SL-16 R/B               
2004 500.75 559.43 CZ-4B R/B               
2004 709.31 913.37 CZ-2C R/B               
2004 566.73 692.02 ARIANE 5 R/B            
2005 493.69 509.46 CZ-2D R/B               
2005 451.73 452.67 SUZAKU (ASTRO-EII)      
2006 681.48 684.91 ALOS (DAICHI)           
2006 521.92 626.86 H-2A R/B                
2006 550.91 556.23 RESURS-DK 1             
2006 458.14 478.17 GENESIS 1               
2006 525.44 581.86 CZ-4B R/B               
2007 790.93 875.87 CZ-2C R/B               
2007 628.67 630.56 COSMO-SKYMED 1          
2007 451.12 493.64 GENESIS 2               
2007 849.89 864.60 COSMOS 2428             
2007 848.96 852.61 SL-16 R/B               
2009 488.17 510.14 KORONAS-FOTON           
2011 604.89 685.51 CZ-2C R/B               
2012 574.91 648.51 H-2A R/B                
2013 302.70 780.50 CUSAT 2 & FALCON 9 R/B  
2013 598.27 622.21 SHIJIAN-16 (SJ-16)      
2013 355.02 381.95 CZ-2C R/B               
2014 421.87 616.61 SL-4 R/B                
2014 636.91 639.19 ALOS-2                  
2014 357.11 389.70 SL-27 R/B               
2015 629.39 633.54 YAOGAN-29               
2016 556.71 572.52 ASTRO-H (HITOMI)        
2017 523.09 524.49 HXMT (HUIYAN)           
2018 455.11 538.11 CZ-2C R/B               
2018 628.64 630.72 SAOCOM 1A               
2018 503.09 566.05 H-2A R/B                
2020 628.74 630.64 SAOCOM 1B               
2021 376.22 390.21 CSS (TIANHE)            
2021 465.82 477.25 COSMOS 2550             
2022 379.51 422.51 2022-019U               
2022 452.20 569.38 CZ-2C R/B               
2022 309.46 326.68 CZ-2C R/B               
2023 566.80 580.89 XRISM                   

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Bob Meyes 2024-3-26

在 MATLAB Online 中打开

I tried to rewrite the fucntions as follows but I got an error statement that Function definitions in a script must appear at the end of the file

% Fetch TLE data from the URL
url_recent = 'https://celestrak.org/NORAD/elements/gp.php?GROUP=visual&FORMAT=tle';
line_list = string(splitlines(webread(url_recent)));
% Ensure line_list has a multiple of 3 number of lines for proper reshaping
line_list = line_list(1:floor(numel(line_list)/3)*3);
% Reshape the line list to separate each TLE into its own column
tle_data = reshape(line_list, 3, []);
function launch_year = launch_yr_4d(y2d)
launch_year = (y2d >= 24) .* (1900 + y2d) + (y2d < 24) .* (2000 + y2d);
end
function apogee_height = apogee(mean_motion, eccentricity)
earth_mean_radius = 6371.0; % Earth's mean radius in kilometers
apogee_height = (8681663.653 ./ mean_motion) .^ (2/3) .* (1 + eccentricity) - earth_mean_radius;
end
function perigee_height = perigee(mean_motion, eccentricity)
earth_mean_radius = 6371.0; % Earth's mean radius in kilometers
perigee_height = (8681663.653 ./ mean_motion) .^ (2/3) .* (1 - eccentricity) - earth_mean_radius;
end
% Extract satellite numbers, launch years, eccentricities, and mean motions in batches
satellite_numbers = str2double(extractBetween(tle_data(2,:), 3, 7));
launch_years_2digit = str2double(extractBetween(tle_data(2,:), 10, 11));
launch_years = launch_yr_4d(launch_years_2digit);
eccentricities = str2double(extractBetween(tle_data(3,:), 27, 33)) * 0.0000001;
mean_motions = str2double(extractBetween(tle_data(3,:), 53, 63));
% Compute perigee and apogee heights in batches
perigee_heights = perigee(mean_motions, eccentricities);
apogee_heights = apogee(mean_motions, eccentricities);
% Convert numerical values to strings with formatting
satNumStr = sprintfc('%05d', satellite_numbers);
launchYearStr = sprintfc('%04d', launch_years);
hpStr = sprintfc('%.2f', hps);
haStr = sprintfc('%.2f', has);
% Concatenate all string parts
outputStrings = strcat(satNumStr, " ", launchYearStr, " ", hpStr, " ", haStr, " ", string(tle_data(1, :)));
% Join and print all strings
fprintf('%s\n', join(outputStrings, newline));

Dyuman Joshi 2024-3-26

在 MATLAB Online 中打开

Shift the functions to the end/bottom of the script and then run your code.

Though there is atleast one undefined variable in your code -

% Fetch TLE data from the URL
url_recent = 'https://celestrak.org/NORAD/elements/gp.php?GROUP=visual&FORMAT=tle';
line_list = string(splitlines(webread(url_recent)));
% Ensure line_list has a multiple of 3 number of lines for proper reshaping
line_list = line_list(1:floor(numel(line_list)/3)*3);
% Reshape the line list to separate each TLE into its own column
tle_data = reshape(line_list, 3, []);
% Extract satellite numbers, launch years, eccentricities, and mean motions in batches
satellite_numbers = str2double(extractBetween(tle_data(2,:), 3, 7));
launch_years_2digit = str2double(extractBetween(tle_data(2,:), 10, 11));
launch_years = launch_yr_4d(launch_years_2digit);
eccentricities = str2double(extractBetween(tle_data(3,:), 27, 33)) * 0.0000001;
mean_motions = str2double(extractBetween(tle_data(3,:), 53, 63));
% Compute perigee and apogee heights in batches
perigee_heights = perigee(mean_motions, eccentricities);
apogee_heights = apogee(mean_motions, eccentricities);
% Convert numerical values to strings with formatting
satNumStr = sprintfc('%05d', satellite_numbers);
launchYearStr = sprintfc('%04d', launch_years);
hpStr = sprintfc('%.2f', hps);
Unrecognized function or variable 'hps'.
haStr = sprintfc('%.2f', has);
% Concatenate all string parts
outputStrings = strcat(satNumStr, " ", launchYearStr, " ", hpStr, " ", haStr, " ", string(tle_data(1, :)));
% Join and print all strings
fprintf('%s\n', join(outputStrings, newline));
%Any and all functions definitions in a script shifted to bottom of the
%script page
function launch_year = launch_yr_4d(y2d)
launch_year = (y2d >= 24) .* (1900 + y2d) + (y2d < 24) .* (2000 + y2d);
end
function apogee_height = apogee(mean_motion, eccentricity)
earth_mean_radius = 6371.0; % Earth's mean radius in kilometers
apogee_height = (8681663.653 ./ mean_motion) .^ (2/3) .* (1 + eccentricity) - earth_mean_radius;
end
function perigee_height = perigee(mean_motion, eccentricity)
earth_mean_radius = 6371.0; % Earth's mean radius in kilometers
perigee_height = (8681663.653 ./ mean_motion) .^ (2/3) .* (1 - eccentricity) - earth_mean_radius;
end

Bob Meyes 2024-3-26

在 MATLAB Online 中打开

Okay thanks, but is there a way to rewrite the code so a reshape function is not needed. This is the code I have right now for reference

% Fetch TLE data from the URL
url_recent = 'https://celestrak.org/NORAD/elements/gp.php?GROUP=visual&FORMAT=tle';
line_list = string(splitlines(webread(url_recent)));
% Ensure line_list has a multiple of 3 number of lines for proper reshaping
line_list = line_list(1:floor(numel(line_list)/3)*3);
% Reshape the line list to separate each TLE into its own column
tle_data = reshape(line_list, 3, []);
% Extract satellite numbers, launch years, eccentricities, and mean motions in batches
satellite_numbers = str2double(extractBetween(tle_data(2,:), 3, 7));
launch_years_2digit = str2double(extractBetween(tle_data(2,:), 10, 11));
launch_years = launch_yr_4d(launch_years_2digit);
eccentricities = str2double(extractBetween(tle_data(3,:), 27, 33)) * 0.0000001;
mean_motions = str2double(extractBetween(tle_data(3,:), 53, 63));
% Compute perigee and apogee heights in batches
perigee_heights = perigee(mean_motions, eccentricities);
apogee_heights = apogee(mean_motions, eccentricities);
% Convert numerical values to strings with formatting
satNumStr = sprintfc('%05d', satellite_numbers);
launchYearStr = sprintfc('%04d', launch_years);
hpStr = sprintfc('%.2f', perigee_heights);
haStr = sprintfc('%.2f', apogee_heights);
% Concatenate all string parts
outputStrings = strcat(satNumStr, " ", launchYearStr, " ", hpStr, " ", haStr, " ", string(tle_data(1, :)));
% Join and print all strings
fprintf('%s\n', join(outputStrings, newline));
%Define functions
function launch_year = launch_yr_4d(y2d)
launch_year = (y2d >= 24) .* (1900 + y2d) + (y2d < 24) .* (2000 + y2d);
end
function apogee_height = apogee(mean_motion, eccentricity)
earth_mean_radius = 6371.0; % Earth's mean radius in kilometers
apogee_height = (8681663.653 ./ mean_motion) .^ (2/3) .* (1 + eccentricity) - earth_mean_radius;
end
function perigee_height = perigee(mean_motion, eccentricity)
earth_mean_radius = 6371.0; % Earth's mean radius in kilometers
perigee_height = (8681663.653 ./ mean_motion) .^ (2/3) .* (1 - eccentricity) - earth_mean_radius;
end