Skip to main content

list manipulation - Select rows from table by keys


I am looking for a way to iteratively select all sublists with the same ID (my 1st column, residual columns are AbsoluteTime entries). First, I obtained the list of unique IDs with Union. Then I want to use this list for the selection task. I assume that it must work with Sequence and ReplaceAll, but could not make it work. Here's what I have so far:


ticketList = Union[dataList[[1 ;;, 1]]];
tempList = Select[dataList, #1[[1]] == x &] /. x ->  Sequence[ticketList];

My ultimate goal is to build up a TemporalData array with all items which each belong to the same ID.


My data is has dimensions n x m. The ticket list has dimension t. The resulting table should have dimensions t x i x m, where i is the cardinality of items with the same ID, and the i's sum to n. I assumed, that I can then map TemporalData on every t-th item in order to build the temporal list.



I searched the site but didn't find a previous question that seem to address my problem. Maybe I misunderstood the use cases of similiar questions.



Answer



Here's an attempt to address your question based on the sort of data I imagine you have in mind. First, some data. Note: the integers are understood to be ID's.


times = RandomReal[{0, 100}, {20, 5}];
ids = RandomInteger[4, 20];
data = Transpose[Prepend[Transpose[times], ids]]


{{1, 95.2049, 98.1609, 35.1946, 32.636, 81.2383}, {3, 92.8072, 36.0249, 68.3793, 54.1311, 95.1051}, {3, 4.26078, 47.9919, 31.627, 53.0064, 96.8995}, {4, 18.2792, 94.4752, 5.66575, 5.62435, 35.8945}, {4, 67.4149, 68.1577, 25.281, 17.8322, 15.3123}, {2, 77.6343, 35.3486, 81.3541, 73.6091, 51.4884}, {0, 28.5346, 29.2705, 78.9446, 32.2112, 7.05296}, {4, 91.9405, 79.4176, 75.6947, 72.1069, 5.94247}, {2, 11.0662, 24.4381, 79.5328, 20.2195, 79.4703}, {0, 61.6779, 73.8532, 61.5861, 7.79641, 38.3836}, {4, 52.3064, 95.9954, 62.3701, 34.7654, 99.8931}, {2, 92.6636, 57.8744, 23.4167, 76.3724, 44.8631}, {2, 73.7149, 84.6716, 36.1234, 89.5432, 39.8183}, {3, 50.4444, 7.98911, 69.4092, 96.3191, 79.6566}, {3, 41.2261, 58.5009, 57.7989, 58.9187, 8.87187}, {4, 53.5552, 11.3278, 8.24034, 67.3065, 19.4648}, {2, 19.9501, 30.5649, 73.9395, 13.3722, 36.5546}, {3, 96.5631, 19.1948, 23.226, 92.8776, 64.4002}, {0, 65.9084, 10.2902, 8.83754, 93.0831, 36.464}, {1, 18.2795, 12.4673, 42.0253, 39.8816, 50.8252}}




Now to gather the records that have the same id:


GatherBy[data, First]//TableForm

Mathematica graphics


Comments

Post a Comment

Popular posts from this blog

plotting - Filling between two spheres in SphericalPlot3D

Manipulate[ SphericalPlot3D[{1, 2 - n}, {θ, 0, Pi}, {ϕ, 0, 1.5 Pi}, Mesh -> None, PlotPoints -> 15, PlotRange -> {-2.2, 2.2}], {n, 0, 1}] I cant' seem to be able to make a filling between two spheres. I've already tried the obvious Filling -> {1 -> {2}} but Mathematica doesn't seem to like that option. Is there any easy way around this or ... Answer There is no built-in filling in SphericalPlot3D . One option is to use ParametricPlot3D to draw the surfaces between the two shells: Manipulate[ Show[SphericalPlot3D[{1, 2 - n}, {θ, 0, Pi}, {ϕ, 0, 1.5 Pi}, PlotPoints -> 15, PlotRange -> {-2.2, 2.2}], ParametricPlot3D[{ r {Sin[t] Cos[1.5 Pi], Sin[t] Sin[1.5 Pi], Cos[t]}, r {Sin[t] Cos[0 Pi], Sin[t] Sin[0 Pi], Cos[t]}}, {r, 1, 2 - n}, {t, 0, Pi}, PlotStyle -> Yellow, Mesh -> {2, 15}]], {n, 0, 1}]
Post a Comment
Read more

plotting - Plot 4D data with color as 4th dimension

I have a list of 4D data (x position, y position, amplitude, wavelength). I want to plot x, y, and amplitude on a 3D plot and have the color of the points correspond to the wavelength. I have seen many examples using functions to define color but my wavelength cannot be expressed by an analytic function. Is there a simple way to do this? Answer Here a another possible way to visualize 4D data: data = Flatten[Table[{x, y, x^2 + y^2, Sin[x - y]}, {x, -Pi, Pi,Pi/10}, {y,-Pi,Pi, Pi/10}], 1]; You can use the function Point along with VertexColors . Now the points are places using the first three elements and the color is determined by the fourth. In this case I used Hue, but you can use whatever you prefer. Graphics3D[ Point[data[[All, 1 ;; 3]], VertexColors -> Hue /@ data[[All, 4]]], Axes -> True, BoxRatios -> {1, 1, 1/GoldenRatio}]
Post a Comment
Read more

plotting - Mathematica: 3D plot based on combined 2D graphs

I have several sigmoidal fits to 3 different datasets, with mean fit predictions plus the 95% confidence limits (not symmetrical around the mean) and the actual data. I would now like to show these different 2D plots projected in 3D as in but then using proper perspective. In the link here they give some solutions to combine the plots using isometric perspective, but I would like to use proper 3 point perspective. Any thoughts? Also any way to show the mean points per time point for each series plus or minus the standard error on the mean would be cool too, either using points+vertical bars, or using spheres plus tubes. Below are some test data and the fit function I am using. Note that I am working on a logit(proportion) scale and that the final vertical scale is Log10(percentage). (* some test data *) data = Table[Null, {i, 4}]; data[[1]] = {{1, -5.8}, {2, -5.4}, {3, -0.8}, {4, -0.2}, {5, 4.6}, {1, -6.4}, {2, -5.6}, {3, -0.7}, {4, 0.04}, {5, 1.0}, {1, -6.8}, {2, -4.7}, {3, -1.
Post a Comment
Read more