From 8811c7d86c69094b63e82bcc04dc87d60c28531f Mon Sep 17 00:00:00 2001 From: simonharnqvist <45334810+simonharnqvist@users.noreply.github.com> Date: Wed, 25 Mar 2026 16:28:20 +0000 Subject: [PATCH] NaN -> nan update --- _episodes/02-numpy.md | 14 +++++++------- 1 file changed, 7 insertions(+), 7 deletions(-) diff --git a/_episodes/02-numpy.md b/_episodes/02-numpy.md index eae39d1c4e..48a4ae84e1 100644 --- a/_episodes/02-numpy.md +++ b/_episodes/02-numpy.md @@ -429,7 +429,7 @@ Wave height standard deviation: 1.1440155050316319 > for example: `help(numpy.cumprod)`. {: .callout} -> ## What about NaNs? +> ## What about `nan`s? > > In real datasets, particularly ones which come from observational data, it's quite common > for some values to be missing. There are various strategies to deal with missing values; one of which is to @@ -437,12 +437,12 @@ Wave height standard deviation: 1.1440155050316319 > Kelvin, or 999 for a missing latitude or longitude value). However, the issue with this is that > we would need to check for these values before calculating any summary statistic. > -> Instead, we can use NumPy's `NaN` ("not a number") value, which will tell NumPy that these are -> values that need to be dealt with in a special manner. NumPy also provides various functions to help deal with NaNs. -> However, we can't use NumPy's normal statistical functions on any array that contains a NaN, as this returns a NaN: +> Instead, we can use NumPy's `nan` ("not a number") value, which will tell NumPy that these are +> values that need to be dealt with in a special manner. NumPy also provides various functions to help deal with nans. +> However, we can't use NumPy's normal statistical functions on any array that contains a nan, as this returns a nan: > > ~~~ -> data = numpy.array([[1,2,3],[1,numpy.NaN,3],[1,2,3]]) +> data = numpy.array([[1,2,3],[1,numpy.nan,3],[1,2,3]]) > numpy.mean(data) > ~~~ > {: .language-python} @@ -455,7 +455,7 @@ Wave height standard deviation: 1.1440155050316319 > Instead, we need to use the NumPy function `nanmean`: > > ~~~ -> data = numpy.array([[1,2,3],[1,numpy.NaN,3],[1,2,3]]) +> data = numpy.array([[1,2,3],[1,numpy.nan,3],[1,2,3]]) > numpy.nanmean(data) > ~~~ > {: .language-python} @@ -465,7 +465,7 @@ Wave height standard deviation: 1.1440155050316319 > ~~~ > {: .output} > -> If, at a later date, we'd like to replace all the NaNs with a sensible numerical value +> If, at a later date, we'd like to replace all the `nan`s with a sensible numerical value > (e.g. the mean of the column), NumPy also provides functions that can help with this {: .callout}