# Latest

**URL:** https://discourse.julialang.org/latest.md?page=1228

[Latest](https://discourse.julialang.org/latest.md) · [Categories](https://discourse.julialang.org/categories.md) · [Tags](https://discourse.julialang.org/tags.md)

**Page:** 1229

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## [LocalRegistry 0.5](https://discourse.julialang.org/t/localregistry-0-5/70304)

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**Author:** [@GunnarFarneback](https://discourse.julialang.org/u/GunnarFarneback)\
**Replies:** 0\
**Last updated:** [October 24, 2021, 8:17pm UTC](https://discourse.julialang.org/t/localregistry-0-5/70304 "2021-10-24T20:17:48Z")

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LocalRegistry lets you create and maintain local registries for Julia packages. Version 0.5.0 is a (somewhat marginally) breaking release. Breaking Changes The rules for how to interpret the registry argument have ch…

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## [Query for seeing dates on which integers in another column change](https://discourse.julialang.org/t/query-for-seeing-dates-on-which-integers-in-another-column-change/70286)

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**Author:** [@Nash](https://discourse.julialang.org/u/Nash)\
**Replies:** 2\
**Last updated:** [October 24, 2021, 8:14pm UTC](https://discourse.julialang.org/t/query-for-seeing-dates-on-which-integers-in-another-column-change/70286 "2021-10-24T20:14:29Z")

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Suppose I have a Dataframe. One of the columns contains Dates sorted from low to high. Another columns contains integers. On particular dates, the value in the integer-column changes. What query will allow me to find see…

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## [Covariance from DataFrame or TimeArray](https://discourse.julialang.org/t/covariance-from-dataframe-or-timearray/48375)

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**Author:** [@rvaj](https://discourse.julialang.org/u/rvaj)\
**Replies:** 17\
**Last updated:** [October 24, 2021, 7:52pm UTC](https://discourse.julialang.org/t/covariance-from-dataframe-or-timearray/48375 "2021-10-24T19:52:55Z")

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I have a large data set consisting of daily stock returns over 30 years and 7000 stocks. The time series do not align with each other across the set (i.e. dropmissing(data) returns no rows). If I compute the covariance…

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## [Gradient evaluation with ForwardDiff and LoopVectorization](https://discourse.julialang.org/t/gradient-evaluation-with-forwarddiff-and-loopvectorization/70262)

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**Author:** [@Gravlax](https://discourse.julialang.org/u/Gravlax)\
**Replies:** 2\
**Last updated:** [October 24, 2021, 6:47pm UTC](https://discourse.julialang.org/t/gradient-evaluation-with-forwarddiff-and-loopvectorization/70262 "2021-10-24T18:47:14Z")

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Hi everyone, I am trying use the ForwardDiff.gradient! function to compute the in-place gradient of a function F with regard to 3 parameters. F has ncx entries and the function has 3 parameters per entry. I explicitly …

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## [StringDocument() of the TextAnalysis package](https://discourse.julialang.org/t/stringdocument-of-the-textanalysis-package/62589)

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**Author:** [@Alex\_Tantos](https://discourse.julialang.org/u/Alex_Tantos)\
**Replies:** 3\
**Last updated:** [October 24, 2021, 5:52pm UTC](https://discourse.julialang.org/t/stringdocument-of-the-textanalysis-package/62589 "2021-10-24T17:52:50Z")

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Hi there! Has anybody been using the StringDocument() function of the TextAnalysis package for unicode encoded language strings? However, if I use StringDocument() with a readin (greek) string from a file with the read…

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## [Random warning messages with Catalyst](https://discourse.julialang.org/t/random-warning-messages-with-catalyst/66289)

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**Author:** [@lmiq](https://discourse.julialang.org/u/lmiq)\
**Replies:** 11\
**Last updated:** [October 24, 2021, 5:22pm UTC](https://discourse.julialang.org/t/random-warning-messages-with-catalyst/66289 "2021-10-24T17:22:49Z")

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I keep getting, sort of randomly, these warning messages when using Catalyst. I have erased and reinstalled all my Julia packages and the error persisted. Any idea what can it be? WARNING: Method definition Type##kw(Any…

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## [Packages to compute model evidence in the Julia MCMC ecosystem?](https://discourse.julialang.org/t/packages-to-compute-model-evidence-in-the-julia-mcmc-ecosystem/68922)

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**Author:** [@sami1](https://discourse.julialang.org/u/sami1)\
**Replies:** 5\
**Last updated:** [October 24, 2021, 5:14pm UTC](https://discourse.julialang.org/t/packages-to-compute-model-evidence-in-the-julia-mcmc-ecosystem/68922 "2021-10-24T17:14:30Z")

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Hi, I’m interested in estimating model evidence (marginal likelihood) for probabilistic models (using the DynamicPPL framework, but let me know if there is something on this matter with Soss.jl). The only available solu…

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## [How to line break a very long 1-row string array?](https://discourse.julialang.org/t/how-to-line-break-a-very-long-1-row-string-array/70287)

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**Author:** [@leon](https://discourse.julialang.org/u/leon)\
**Replies:** 10\
**Last updated:** [October 24, 2021, 5:08pm UTC](https://discourse.julialang.org/t/how-to-line-break-a-very-long-1-row-string-array/70287 "2021-10-24T17:08:18Z")

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I have a unit row like the below. You see “” because some of the units are none. For example, there is no unit for Year. row2 = \["" "" "" "umol/kg" "" "" "kg/m3" "decimal degrees"\]; In reality it is much longer, so I …

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## [After making some changes, I can no longer import Pkg.CSV](https://discourse.julialang.org/t/after-making-some-changes-i-can-no-longer-import-pkg-csv/70267)

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**Author:** [@CBrauer](https://discourse.julialang.org/u/CBrauer)\
**Replies:** 10\
**Last updated:** [October 24, 2021, 4:34pm UTC](https://discourse.julialang.org/t/after-making-some-changes-i-can-no-longer-import-pkg-csv/70267 "2021-10-24T16:34:16Z")

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Hey, My notebook was working fine, but after some changes, I’m now getting an error. Please help me to fix this problem. The first few cells of my Jupyter Notebook are shown below: Charles

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## [3d bars makie, colors and meshes](https://discourse.julialang.org/t/3d-bars-makie-colors-and-meshes/70283)

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**Author:** [@lazarusA](https://discourse.julialang.org/u/lazarusA)\
**Replies:** 9\
**Last updated:** [October 24, 2021, 3:33pm UTC](https://discourse.julialang.org/t/3d-bars-makie-colors-and-meshes/70283 "2021-10-24T15:33:09Z")

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Probably, the following could be done without to much effort, but I don’t seem to find the right way to do it :smiley: A way to merge all Rect3 meshes? Plotting one by one becomes really slow after a while. Add a color…

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## [Efficient way of computing norm between all the rows of a matrix](https://discourse.julialang.org/t/efficient-way-of-computing-norm-between-all-the-rows-of-a-matrix/70277)

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**Author:** [@vinicius\_de\_lima](https://discourse.julialang.org/u/vinicius_de_lima)\
**Replies:** 5\
**Last updated:** [October 24, 2021, 12:28pm UTC](https://discourse.julialang.org/t/efficient-way-of-computing-norm-between-all-the-rows-of-a-matrix/70277 "2021-10-24T12:28:44Z")

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I stored points in the rows of a 999900 x 2 matrix and tried to count the number of pairs of these points that are at a distance smaller than r, but my implementation was too slow, there is a more efficient way to achiev…

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## [How to add a unit row to a CSV file through dataframe?](https://discourse.julialang.org/t/how-to-add-a-unit-row-to-a-csv-file-through-dataframe/70241)

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**Author:** [@leon](https://discourse.julialang.org/u/leon)\
**Replies:** 7\
**Last updated:** [October 24, 2021, 11:49am UTC](https://discourse.julialang.org/t/how-to-add-a-unit-row-to-a-csv-file-through-dataframe/70241 "2021-10-24T11:49:12Z")

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I need to write my matrix into a CSV file, due to the large size (~200 MB), it will be very hard to open it using Excel later on and manually add a 2nd row for the unit information. Is there a better way to add such a r…

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## [Extremely long times fetching Julia General registry on macOS](https://discourse.julialang.org/t/extremely-long-times-fetching-julia-general-registry-on-macos/70123)

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**Author:** [@CameronBieganek](https://discourse.julialang.org/u/CameronBieganek)\
**Replies:** 3\
**Last updated:** [October 24, 2021, 9:38am UTC](https://discourse.julialang.org/t/extremely-long-times-fetching-julia-general-registry-on-macos/70123 "2021-10-24T09:38:46Z")

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Has anyone had this problem? This is on my personal laptop, which is on a somewhat old version of macOS (version 10.13.6).

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## [Heatmap with log scale colorbar (cscale)](https://discourse.julialang.org/t/heatmap-with-log-scale-colorbar-cscale/63018)

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**Author:** [@ederag](https://discourse.julialang.org/u/ederag)\
**Replies:** 5\
**Last updated:** [October 24, 2021, 9:19am UTC](https://discourse.julialang.org/t/heatmap-with-log-scale-colorbar-cscale/63018 "2021-10-24T09:19:38Z")

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Makie is awesome, looks like everything is doable :slightly\_smiling\_face:, for instance, this heatmap with log scale color axis (exactly what I wanted): Code for the above figure# in one Pluto.jl cell using CairoMak…

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## [Describing a particular second-order equation in DifferentialEquations.jl](https://discourse.julialang.org/t/describing-a-particular-second-order-equation-in-differentialequations-jl/53253)

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**Author:** [@anC](https://discourse.julialang.org/u/anC)\
**Replies:** 8\
**Last updated:** [October 24, 2021, 7:49am UTC](https://discourse.julialang.org/t/describing-a-particular-second-order-equation-in-differentialequations-jl/53253 "2021-10-24T07:49:15Z")

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I am using DifferentialEquations.jl . If I wanted to solve a simple second order equation of the form: a t^2 f’‘(t) + b t f’(t) +c = 0 (for a,b,c real constants) I think the way to describe the problem in dif…

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## [Count instances of type](https://discourse.julialang.org/t/count-instances-of-type/70279)

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**Author:** [@jzr](https://discourse.julialang.org/u/jzr)\
**Replies:** 2\
**Last updated:** [October 24, 2021, 6:03am UTC](https://discourse.julialang.org/t/count-instances-of-type/70279 "2021-10-24T06:03:45Z")

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Is it possible to ask Julia how many instances of an arbitrary type T are alive?

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## [Memory usage of Zygote in list comprehensions](https://discourse.julialang.org/t/memory-usage-of-zygote-in-list-comprehensions/70278)

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**Author:** [@tictaccat](https://discourse.julialang.org/u/tictaccat)\
**Replies:** 4\
**Last updated:** [October 24, 2021, 3:06am UTC](https://discourse.julialang.org/t/memory-usage-of-zygote-in-list-comprehensions/70278 "2021-10-24T03:06:08Z")

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Hi! I’ve been running into memory/runtime issues with Zygote when using list comprehensions. I’d like to ask a simple question. Suppose x is an array of length n. When Zygote differentiates backwards through the followin…

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## [Fill under line to vertical axis in Plots.jl](https://discourse.julialang.org/t/fill-under-line-to-vertical-axis-in-plots-jl/70251)

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**Author:** [@babaq](https://discourse.julialang.org/u/babaq)\
**Replies:** 2\
**Last updated:** [October 23, 2021, 11:07pm UTC](https://discourse.julialang.org/t/fill-under-line-to-vertical-axis-in-plots-jl/70251 "2021-10-23T23:07:05Z")

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anyone tried to plot a line and fill to the y axis using Plots? similar like this:

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## [How to use DiffEqFlux on DAEProblem](https://discourse.julialang.org/t/how-to-use-diffeqflux-on-daeproblem/70276)

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**Author:** [@clm](https://discourse.julialang.org/u/clm)\
**Replies:** 0\
**Last updated:** [October 23, 2021, 11:02pm UTC](https://discourse.julialang.org/t/how-to-use-diffeqflux-on-daeproblem/70276 "2021-10-23T23:02:01Z")

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I’m trying to use diffeqflux on differential algebraic equations. I know there is an example in the diffeqflux docs, but there they use constant mass matrices. I want to have the option to use non-constant matrices. Ulti…

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## [Replacing some elements of an array with corresponding elements from another array](https://discourse.julialang.org/t/replacing-some-elements-of-an-array-with-corresponding-elements-from-another-array/70248)

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**Author:** [@leon](https://discourse.julialang.org/u/leon)\
**Replies:** 17\
**Last updated:** [October 23, 2021, 10:57pm UTC](https://discourse.julialang.org/t/replacing-some-elements-of-an-array-with-corresponding-elements-from-another-array/70248 "2021-10-23T22:57:21Z")

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My goal is to replace any elements in array A that are either NaN or \<0 with the corresponding elements in Array B. Below is my code: A = \[1, 2.1, -5, 6, -3, 8, NaN\]; B = \[8, 8.2, 8, 8, 8, 8, 8\]; C = replace!(x -\> (x\<…

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## [Extrapolate vectors](https://discourse.julialang.org/t/extrapolate-vectors/70239)

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**Author:** [@lostboy](https://discourse.julialang.org/u/lostboy)\
**Replies:** 7\
**Last updated:** [October 23, 2021, 9:34pm UTC](https://discourse.julialang.org/t/extrapolate-vectors/70239 "2021-10-23T21:34:35Z")

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hello everyone. i’m dealing with some struggles when programming in Julia since I come from matlab. I need to extrapolate this plot so I can get rho(0). any help? version 1.6.3

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## [How to intersect a Cartesian Index with a regular index?](https://discourse.julialang.org/t/how-to-intersect-a-cartesian-index-with-a-regular-index/70270)

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**Author:** [@leon](https://discourse.julialang.org/u/leon)\
**Replies:** 6\
**Last updated:** [October 23, 2021, 9:31pm UTC](https://discourse.julialang.org/t/how-to-intersect-a-cartesian-index-with-a-regular-index/70270 "2021-10-23T21:31:36Z")

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For example, I have an Index1 that is generated from this: A = \[NaN, 2.1, NaN, -3, 8, 65, NaN\]; f1(A) = \[idx for idx in CartesianIndices(A) if @inbounds (isnan(A\[idx\])) \]; Index1 = f1(A); Results of Index1: Index1 = 3…

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## [History mode for Pkg](https://discourse.julialang.org/t/history-mode-for-pkg/70256)

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**Author:** [@jules](https://discourse.julialang.org/u/jules)\
**Replies:** 7\
**Last updated:** [October 23, 2021, 7:22pm UTC](https://discourse.julialang.org/t/history-mode-for-pkg/70256 "2021-10-23T19:22:03Z")

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I thought it could be useful to add a history mode to Pkg. The goal would be to reset the registry to the state it had at some specific date, and then all packages you add would be limited to their versions at the time. …

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## [CategoricalArray levels! allowmissing](https://discourse.julialang.org/t/categoricalarray-levels-allowmissing/67960)

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**Author:** [@jzr](https://discourse.julialang.org/u/jzr)\
**Replies:** 3\
**Last updated:** [October 23, 2021, 6:23pm UTC](https://discourse.julialang.org/t/categoricalarray-levels-allowmissing/67960 "2021-10-23T18:23:59Z")

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I am ordering the categories according to their frequency. What is wrong? using CategoricalArrays, FreqTables x = \["a", "b", "c", "c", missing\] cx = CategoricalArray(x) lvls = names(sort(freqtable(collect(skipmissing(cx…

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## [Row index in a dataframe](https://discourse.julialang.org/t/row-index-in-a-dataframe/70265)

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**Author:** [@corny85](https://discourse.julialang.org/u/corny85)\
**Replies:** 4\
**Last updated:** [October 23, 2021, 5:55pm UTC](https://discourse.julialang.org/t/row-index-in-a-dataframe/70265 "2021-10-23T17:55:09Z")

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Hello, I have a dataframe that i sorted in order to get the maximum (of values in a column). Now, i want to get the index corresponding to this maximum in the initial dataframe. I’ve tried a lot of things with rownumb…

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## [Performance deviations when summing an integer matrix](https://discourse.julialang.org/t/performance-deviations-when-summing-an-integer-matrix/70260)

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**Author:** [@goerch](https://discourse.julialang.org/u/goerch)\
**Replies:** 3\
**Last updated:** [October 23, 2021, 5:29pm UTC](https://discourse.julialang.org/t/performance-deviations-when-summing-an-integer-matrix/70260 "2021-10-23T17:29:07Z")

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The following program using Tables using CSV using BenchmarkTools function process1(a::Matrix{Int}) count = 0 for i in 1:size(a, 1) for j in 1:size(a, 2) count += a\[i, j\] end end…

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## [What's going on with exp() and --math-mode=fast?](https://discourse.julialang.org/t/whats-going-on-with-exp-and-math-mode-fast/64619)

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**Author:** [@robsmith11](https://discourse.julialang.org/u/robsmith11)\
**Replies:** 29\
**Last updated:** [October 23, 2021, 5:13pm UTC](https://discourse.julialang.org/t/whats-going-on-with-exp-and-math-mode-fast/64619 "2021-10-23T17:13:28Z")

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I was surprised to see results that are significantly different (by much more than I would except when using normal ffast-math optimizations) when running julia with --math-mode=fast. It seems like a very rough approxim…

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## [Find indices meeting multiple criteria searching from multiple arrays](https://discourse.julialang.org/t/find-indices-meeting-multiple-criteria-searching-from-multiple-arrays/51228)

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**Author:** [@dalarev](https://discourse.julialang.org/u/dalarev)\
**Replies:** 6\
**Last updated:** [October 23, 2021, 3:49pm UTC](https://discourse.julialang.org/t/find-indices-meeting-multiple-criteria-searching-from-multiple-arrays/51228 "2021-10-23T15:49:59Z")

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How do I find the indices that meet both A \> 0 and B \> 0? In this MWE, I want the answer CartesianIndex(3,3), since that’s the only location that satisfies both conditions. julia\> A = repeat(-1:1',1,3) 3×3 Array{Int64,…

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## [Cumulative sum on rows of a dataframe](https://discourse.julialang.org/t/cumulative-sum-on-rows-of-a-dataframe/70242)

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**Author:** [@corny85](https://discourse.julialang.org/u/corny85)\
**Replies:** 3\
**Last updated:** [October 23, 2021, 2:35pm UTC](https://discourse.julialang.org/t/cumulative-sum-on-rows-of-a-dataframe/70242 "2021-10-23T14:35:10Z")

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I am a beginner in Julia… I am trying to add a new column with cumulative values in regards with some other columns function weighted\_sum(input\_df::DataFrame, weight::Array{Int64,1}, start\_col=2) somme\_df = deepcop…

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## [Gradients of FFT](https://discourse.julialang.org/t/gradients-of-fft/70223)

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**Author:** [@maedoc](https://discourse.julialang.org/u/maedoc)\
**Replies:** 5\
**Last updated:** [October 23, 2021, 12:52pm UTC](https://discourse.julialang.org/t/gradients-of-fft/70223 "2021-10-23T12:52:30Z")

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I tried to expand the DiffEqFlux page’s model to a simple one involving an FFT, but I can’t seem to get it working with any of the sensalg options. Here’s what I’ve got, using FFTW using DiffEqSensitivity, OrdinaryDiff…

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