I have a CSV file with 4 columns with x, y positions for tracks.The 1st column is the ID of the track. The 2nd column is time. 3rd and 4th are X & Y co-ordinates.
Now the X & Y positions change with time (column#2) from 1 to 39. I have written functions (with for loops)that calculate Mean Square Displacement (MSD) for X and Y, as a function of time (column 2).
However, I want to create a 'for' loop in which the code can identify the ID# (from column 1), compute the above mentioned MSD for X & Y as function of time frame, for the first track. Then repeat this task for track#2 from column 1 and so on. Ultimately, write all of this data into a csv finally.
This would be a nested for loop where for every track# from col#1, it will compute MSD values.
Hope the problem statement is clear.
I am presenting data from ID#1 and ID#2 for simplification.
[ID Time X Y1 0 1601.335544 496.46088551 1 1581.838184 497.34409511 2 1574.051153 493.21399851 3 1559.965258 504.90568731 4 1559.163646 493.42458321 5 1552.987661 494.28480721 6 1548.432535 497.35843891 7 1538.938784 495.04172671 8 1531.85109 489.06657881 9 1513.806745 504.77040071 10 1510.326674 497.59948631 11 1504.674908 506.20319461 12 1501.314024 509.98077961 13 1486.108431 530.84057351 14 1478.028873 528.98721631 15 1461.280431 555.18103521 16 1457.827357 544.12382951 17 1438.153357 546.18961181 18 1432.669134 536.0799931 19 1421.693967 539.19763681 20 1420.047558 531.83607751 21 1407.484016 552.62129321 22 1401.323039 542.3875261 23 1392.214888 550.1672871 24 1383.369105 538.15342211 25 1376.908441 563.24086661 26 1375.965296 552.18777531 27 1356.164381 565.66036021 28 1350.494881 554.30329031 29 1343.425562 554.21450221 30 1338.147555 543.56547331 31 1319.226209 549.36670581 32 1315.186512 544.14236211 33 1304.524207 559.43541871 34 1307.192095 545.92071451 35 1297.79372 555.02784851 36 1293.623393 548.4954821 37 1272.472404 556.96436191 38 1267.257919 553.43172791 39 1256.48484 564.75478762 0 1938.04852 502.20962722 1 1910.274979 499.41212092 2 1905.602566 494.5641212 3 1892.023117 500.86742782 4 1890.41268 497.25684352 5 1889.370728 497.16787742 6 1879.222251 493.42593242 7 1854.213543 505.90901322 8 1849.009713 506.47187952 9 1827.907196 521.12497662 10 1825.557874 513.50557682 11 1811.655479 514.91857462 12 1804.375201 506.04952052 13 1790.033474 520.97514892 14 1782.406459 512.81877152 15 1768.6465 528.5228782 16 1767.990804 526.00582062 17 1761.603106 535.81459842 18 1753.677501 517.65323472 19 1747.538543 539.05092962 20 1746.84304 531.16239692 21 1742.643159 543.83484592 22 1736.949154 534.78015352 23 1729.319064 542.80457712 24 1724.696825 533.39675612 25 1704.024318 549.78687142 26 1692.312454 544.45823172 27 1686.267143 547.78292182 28 1673.865039 545.0915122 29 1662.986818 562.55775132 30 1656.270704 562.40029872 31 1642.961381 568.32869072 32 1643.388565 563.5122622 33 1631.965059 570.77826272 34 1634.874901 563.75638262 35 1622.105795 574.05279372 36 1616.78351 569.57726352 37 1611.596229 576.49762282 38 1608.866078 567.63588962 39 1591.533636 576.2326799]This is the for loop I use for computing MSD from X & Y.
def calc_msd_np(x): msd = [] for s in range(1,len(x)): dx = x[s:] - x[:-s] msd.append(np.average(dx**2)) return msdprint(calc_msd_np(x))Similarly, I use the for loop for Y-coordinate. Basically, this MSD for X & Y needs to be iterated for each ID.
I am very new to this so figuring out nested loops is very challenging.
