floating point - Why is NaN not equal to NaN? - Stack Overflow
NaN is designed to propagate through all calculations, infecting them like a virus, so if somewhere in your deep, complex calculations you hit upon a NaN, you don't bubble out a seemingly sensible answer. Otherwise by identity NaN/NaN should equal 1, along with all the other consequences like (NaN/NaN)==1, (NaN*1)==NaN, etc.
Why does NaN^0 == 1 - Stack Overflow
2013年7月25日 · NaN preserving and NA preserving work "equivalently" in R, so if you agree that NA^0 should give 1, NaN^0 |-> 1 is a consequence. Indeed (as others said) you should really read R's help pages and not C or IEEE standards, to answer …
How to replace NaN values in a dataframe column
I have a Pandas Dataframe as below: itm Date Amount 67 420 2012-09-30 00:00:00 65211 68 421 2012-09-09 00:00:00 29424 69 421 2012-09-16 00:00:00 29877 70 421
What's the difference between nan, NaN and NAN
2013年7月24日 · Different operating systems and programming languages may have different string representations of NaN: nan NaN NaN% NAN NaNQ NaNS qNaN sNaN 1.#SNAN 1.#QNAN -1.#IND I think having all three is just a convenience. They are the same. >>> np.nan nan >>> np.NaN nan >>> np.NAN nan >>>
python - How to check for NaN values - Stack Overflow
2023年7月13日 · float('nan') represents NaN (not a number). But how do I check for it?
dataframe - Python Pandas: if the data is NaN, then change to be …
2016年7月27日 · row id name age url 1 e1 tom NaN http1 2 e2 john 25 NaN 3 e3 lucy NaN http3 4 e4 tick 29 NaN I want to change the NaN to be 0, else to be 1 in the columns: age, url. My code is following, but it is wrong. import Pandas as pd df[['age', 'url']].applymap(lambda x: 0 …
How to replace numpy.nan to -1 (in one line of code)?
2019年1月20日 · I have z = np.array([4.4, 3, 0, np.nan, -1, 6]) and just can't find any quick and friendly solution for easy replacement. I can't believe it's sometimes such not user friendly language. I tried: np.where(z == np.nan, -1, z) nothing happens. np.nan_to_num(z, -1) changes to zeros. z = [-1 if np.nan(x) else x for x in z] TypeError: 'float' object ...
1.#QNAN error C++ - Stack Overflow
2011年1月6日 · 1#QNAN is a string representation for a "quiet NAN". A "NAN" is "not-a-number" and applies only to floats and doubles. NANs can be very useful actually for representing "null" values (rather than picking some genuine number and hoping for the best you don't need that number for its natural meaning).
python - pandas concat generates nan values - Stack Overflow
2016年10月31日 · I think there is problem with different index values, so where concat cannot align get NaN:. aaa = pd.DataFrame([0,1,0,1,0,0], columns=['prediction'], index=[4,5,8,7,10,12]) print(aaa) prediction 4 0 5 1 8 0 7 1 10 0 12 0 bbb = pd.DataFrame([0,0,1,0,1,1], columns=['groundTruth']) print(bbb) groundTruth 0 0 1 0 2 1 3 0 4 1 5 1 print (pd.concat([aaa, …
javascript - ¿Por qué NaN != NaN? - Stack Overflow en español
2016年2月23日 · Es como preguntar cual es la diferencia entre un 1 y otro 1?" Esa era la duda planteada, si no hay diferencia; 1 == 1 debería ser NaN == NaN. Actualmente para entender la decisión que tomaron, interpreto que 1 está definido, es el número 1 partícularmente. La definición de NaN en cambio es un conjunto de valores: cualquier cosa, excepto ...