nan

Why does Double.NaN==Double.NaN return false?

由 匆匆过客 提交于 2019-12-17 02:28:30
问题 I was just studying OCPJP questions and I found this strange code: public static void main(String a[]) { System.out.println(Double.NaN==Double.NaN); System.out.println(Double.NaN!=Double.NaN); } When I ran the code, I got: false true How is the output false when we're comparing two things that look the same as each other? What does NaN mean? 回答1: NaN means "Not a Number". Java Language Specification (JLS) Third Edition says: An operation that overflows produces a signed infinity, an operation

pandas DataFrame: replace nan values with average of columns

由 丶灬走出姿态 提交于 2019-12-17 00:47:12
问题 I've got a pandas DataFrame filled mostly with real numbers, but there is a few nan values in it as well. How can I replace the nan s with averages of columns where they are? This question is very similar to this one: numpy array: replace nan values with average of columns but, unfortunately, the solution given there doesn't work for a pandas DataFrame. 回答1: You can simply use DataFrame.fillna to fill the nan 's directly: In [27]: df Out[27]: A B C 0 -0.166919 0.979728 -0.632955 1 -0.297953

pandas DataFrame: replace nan values with average of columns

由 假如想象 提交于 2019-12-17 00:46:23
问题 I've got a pandas DataFrame filled mostly with real numbers, but there is a few nan values in it as well. How can I replace the nan s with averages of columns where they are? This question is very similar to this one: numpy array: replace nan values with average of columns but, unfortunately, the solution given there doesn't work for a pandas DataFrame. 回答1: You can simply use DataFrame.fillna to fill the nan 's directly: In [27]: df Out[27]: A B C 0 -0.166919 0.979728 -0.632955 1 -0.297953

Why does typeof NaN return 'number'?

由 筅森魡賤 提交于 2019-12-16 19:46:48
问题 Just out of curiosity. It doesn't seem very logical that typeof NaN is number. Just like NaN === NaN or NaN == NaN returning false, by the way. Is this one of the peculiarities of javascript, or would there be a reason for this? Edit: thanks for your answers. It's not an easy thing to get ones head around though. Reading answers and the wiki I understood more, but still, a sentence like A comparison with a NaN always returns an unordered result even when comparing with itself. The comparison

Cloud function is writing NaN to firestore

由 泪湿孤枕 提交于 2019-12-14 03:57:29
问题 I created a cloud Function to update a following count every time there is a new follower. However, for whatever reason, NaN gets written to the document instead of an incremented count. What is NaN and why is it getting written instead of the appropriate number? This is my code: var transaction = db.runTransaction(t => { return t.get(countRef) .then(doc => { var new_count = doc.data.following_count + 1; t.update(countRef, { following_count: new_count }); }); }).then(result => { console.log(

When and why number evaluates to NaN, after multiplying, in Javascript?

由 一世执手 提交于 2019-12-14 03:56:24
问题 From my experience I know, that I can get NaN when doing some division or when trying to make a number out of string, when it actually does not contain a number. Are there any other situations, when I can get a NaN . In particular -- is it possible to get it from multiplication? This is a piece of code, that I use in my PhoneGap application: var g = 9.80665; acceleration.x = (acceleration.x * g).toFixed(2); acceleration.y = (acceleration.y * g).toFixed(2); acceleration.z = ((acceleration.z +

NaN errors with bbmle

由 不问归期 提交于 2019-12-14 03:54:33
问题 This question relates to my previous question here and the data set presented in the paper A New Generalization of Linear Exponential Distribution: Theory and Application. For this data, adapting the code proposed by Ben Bolker, we have library(stats4) library(bbmle) x <- scan(textConnection("115 181 255 418 441 461 516 739 743 789 807 865 924 983 1024 1062 1063 1165 1191 1222 1222 1251 1277 1290 1357 1369 1408 1455 1478 1549 1578 1578 1599 1603 1605 1696 1735 1799 1815 1852")) dd <- data

javascript math.round and math.floor work fine in IE and Opera but not Chrome, Safari or Firefox. Getting NaN

由 眉间皱痕 提交于 2019-12-14 03:10:04
问题 Take a look at this fiddle: http://jsfiddle.net/gD3ax/1/ or here's the full markup <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"> <html xmlns="http://www.w3.org/1999/xhtml"> <head> <title>Calculator</title> <meta http-equiv="Content-Type" content="text/html; charset=utf-8" /> <style type="text/css"> .header { font-size: 10pt; color: white; font-weight: 700; text-decoration: none; text-underline-style: none; text-line

Nan to Num Python

由 偶尔善良 提交于 2019-12-13 22:33:12
问题 I have multiple array that for those I calculate a linear regression, but sometimes it gives me 0/0 values which gives me a 'NaN' . I know that to convert an array where there are numbers that are NaN you can convert them using numpy.nan_to_num. But what if I want to convert a single value that's not in a array , but a result of a linear regression calculation? EDIT: It's not a duplicate question (convert nan value to zero ) since I'm referring to a item/result that is not in a array 回答1:

Frustrating code gives Bad real numer in item 1 of list input

由 隐身守侯 提交于 2019-12-13 22:32:10
问题 I am having a nightmare of a time trying to run the following code with the input values below. Now when i run it i get the following error , i read some place that it was due to the fact that my 2,txt file looks messy if i dont save it in a UTF -16 bit, is that something that is possible? At line 11 of file bndry.f (unit = 5, file = '2.txt') Fortran runtime error: Bad real number in item 1 of list input Main code: IMPLICIT NONE INTEGER MS,NS,JS,N,I PARAMETER(MS=50000,NS=50000) REAL*8 S,K,TAU
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