Smoothing by bin boundaries using pandas/numpy - python

I have formed the bins using pandas.cut function. Now, in order to perform smoothing by bin-boundaries, I calculate the minimum and maximum value of each bin using groupby function
Minimum values
date births with noise
bin
A 1959-01-31 23 19.921049
B 1959-01-02 27 25.921175
C 1959-01-01 30 32.064698
D 1959-01-08 35 38.507170
E 1959-01-05 41 45.022163
F 1959-01-13 47 51.821755
G 1959-03-27 56 59.416700
H 1959-09-23 73 70.140119
Maximum values-
date births with noise
bin
A 1959-07-12 30 25.161292
B 1959-12-11 35 31.738422
C 1959-12-27 42 38.447807
D 1959-12-20 48 44.919703
E 1959-12-31 56 51.274550
F 1959-12-30 59 57.515927
G 1959-11-05 68 63.970382
H 1959-09-23 73 70.140119
Now I want to replace the values in my original dataframe. If the value is less than the mean (of its bin) then it is replaced with the min value (for that bin), and if it is greater than the mean then it is replaced with the max value.
My dataframe looks like this-
date births with noise bin smooth_val_mean
0 1959-01-01 35 36.964692 C 35.461173
1 1959-01-02 32 29.861393 B 29.592061
2 1959-01-03 30 27.268515 B 29.592061
3 1959-01-04 31 31.513148 B 29.592061
4 1959-01-05 44 46.194690 E 47.850101
How should I do this using pandas/numpy?

Let's try this function:
def thresh(col):
means = df['bin'].replace(df_mean[col])
mins = df['bin'].replace(df_min[col])
maxs = df['bin'].replace(df_max[col])
signs = np.signs(df[col] - means)
df[f'{col}_smooth'] = np.select((signs==1, signs==-1), (maxs, mins), means)
for col in ['with noise']:
thresh(col)

Related

Sum of the column values if the rows meet the conditions

I am trying to calculate the sum of sales for stores in the same neighborhood based on their geographic coordinates. I have sample data:
data={'ID':['1','2','3','4'],'SALE':[100,120,110,95],'X':[23,22,21,24],'Y':[44,45,41,46],'X_MIN':[22,21,20,23],'Y_MIN':[43,44,40,45],'X_MAX':[24,23,22,25],'Y_MAX':[45,46,42,47]}
ID
SALE
X
Y
X_MIN
Y_MIN
X_MAX
Y_MAX
1
100
23
44
22
43
24
45
2
120
22
45
21
44
23
46
3
110
21
41
20
40
22
42
4
95
24
46
23
45
25
47
X and Y are the coordinates of the store. X and Y with MIN and MAX are the area they cover. For each row, I want to sum sales for all stores that are within the boundaries of the single store. I expect results similar to the table below where SUM for ID 1 is equal 220 because the coordinates (X and Y) are within the MIN and MAX limits of this store for ID 1 and ID 2 while for ID 4 only this one store is between his coordinates so the sum of sales is equal 95.
final={'ID':['1','2','3','4'],'SUM':[220,220,110,95]}
ID
SUM
1
220
2
220
3
110
4
95
What I've tried:
data['SUM'] = data.apply(lambda x: data['SALE'].sum(data[(data['X'] >= x['X_MIN'])&(data['X'] <= x['X_MAX'])&(data['Y'] >= x['Y_MIN'])&(data['Y'] <= x['Y_MAX'])]),axis=1)
Unfortunately the code does not work and I am getting the following error:
TypeError: unhashable type: 'DataFrame'
I am asking for help in solving this problem.
If you put the summation at the end, your solution works:
data['SUM'] = data.apply(lambda x: (data['SALE'][(data['X'] >= x['X_MIN'])&(data['X'] <= x['X_MAX'])&(data['Y'] >= x['Y_MIN'])&(data['Y'] <= x['Y_MAX'])]).sum(),axis=1)
###output of data['SUM']:
###0 220
###1 220
###2 110
###3 95

Plotting of dot points based on np.where condition

I have a lot of data points (in .CSV form) that I am trying to visualize, what I would like to do is to read the csv and read the "result" column, if the value in the corresponding column is positive(I was trying to use np.where condition), I would like to plot the A B C D E F G parameters corresponding to it in such a way that the y-axis is the value of the parameters and x-axis is the name of the parameter.(Something like a dot/scatter plot) I would like to plot all the values in the same graph, Furthermore, if the number of points are more than 20 I would like to use the first 20 points for the plotting.
An example of the type of dataset is below. (Mine contains around 12000 rows)
A B C D E F G result
23 -54 36 27 98 39 80 -0.86
14 44 -16 47 28 29 26 1.65
67 84 26 67 -88 29 10 0.5
-45 14 76 37 68 59 90 0
24 34 56 27 38 79 48 -1.65
Any help in guiding for this would be appreciated !
From your question I assume that your data is a pandas dataframe. In this case you can do the selection with pandas and use its built-in plotting function:
df.loc[df.result>0, df.columns[:-1]].T.plot(ls='', marker='o')
If you want to plot the first 20 rows only, just add [:20] (or better .iloc[:20]) to df.loc.

Check if a row in one DataFrame exist in another, BASED ON SPECIFIC COLUMNS ONLY

I have two Pandas DataFrame with different columns number.
df1 is a single row DataFrame:
a X0 b Y0 c
0 233 100 56 shark -23
df2, instead, is multiple rows Dataframe:
d X0 e f Y0 g h
0 snow 201 32 36 cat 58 336
1 rain 176 99 15 tiger 63 845
2 sun 193 81 42 dog 48 557
3 storm 100 74 18 shark 39 673 # <-- This row
4 cloud 214 56 27 wolf 66 406
I would to verify if the df1's row is in df2, but considering X0 AND Y0 columns only, ignoring all other columns.
In this example the df1's row match the df2's row at index 3, that have 100 in X0 and 'shark' in Y0.
The output for this example is:
True
Note: True/False as output is enough for me, I don't care about index of matched row.
I founded similar questions but all of them check the entire row...
Use df.merge with an if condition check on len:
In [219]: if len(df1[['X0', 'Y0']].merge(df2)):
...: print(True)
...:
True
OR:
In [225]: not (df1[['X0', 'Y0']].merge(df2)).empty
Out[225]: True
Try this:
df2[(df2.X0.isin(df1.X0))&(df2.Y0.isin(df1.Y0))]
Output:
d X0 e f Y0 g h
3 storm 100 74 18 shark 39 673
duplicated
df2.append(df1).duplicated(['X0', 'Y0']).iat[-1]
True
Save a tad bit of time
df2[['X0', 'Y0']].append(df1[['X0', 'Y0']]).duplicated().iat[-1]

Select/Group rows from a data frame with the nearest values for a specific column(s)

I have the two columns in a data frame (you can see a sample down below)
Usually in columns A & B I get 10 to 12 rows with similar values.
So for example: from index 1 to 10 and then from index 11 to 21.
I would like to group these values and get the mean and standard deviation of each group.
I found this following line code where I can get the index of the nearest value. but I don't know how to do this repetitively:
Index = df['A'].sub(df['A'][0]).abs().idxmin()
Anyone has any ideas on how to approach this problem?
A B
1 3652.194531 -1859.805238
2 3739.026566 -1881.965576
3 3742.095325 -1878.707674
4 3747.016899 -1878.728626
5 3746.214554 -1881.270329
6 3750.325368 -1882.915532
7 3748.086576 -1882.406672
8 3751.786422 -1886.489485
9 3755.448968 -1885.695822
10 3753.714126 -1883.504098
11 -337.969554 24.070990
12 -343.019575 23.438956
13 -344.788697 22.250254
14 -346.433460 21.912217
15 -343.228579 22.178519
16 -345.722368 23.037441
17 -345.923108 23.317620
18 -345.526633 21.416528
19 -347.555162 21.315934
20 -347.229210 21.565183
21 -344.575181 22.963298
22 23.611677 -8.499528
23 26.320500 -8.744512
24 24.374874 -10.717384
25 25.885272 -8.982414
26 24.448127 -9.002646
27 23.808744 -9.568390
28 24.717935 -8.491659
29 25.811393 -8.773649
30 25.084683 -8.245354
31 25.345618 -7.508419
32 23.286342 -10.695104
33 -3184.426285 -2533.374402
34 -3209.584366 -2553.310934
35 -3210.898611 -2555.938332
36 -3214.234899 -2558.244347
37 -3216.453616 -2561.863807
38 -3219.326197 -2558.739058
39 -3214.893325 -2560.505207
40 -3194.421934 -2550.186647
41 -3219.728445 -2562.472566
42 -3217.630380 -2562.132186
43 234.800448 -75.157523
44 236.661235 -72.617806
45 238.300501 -71.963103
46 239.127539 -72.797922
47 232.305335 -70.634125
48 238.452197 -73.914015
49 239.091210 -71.035163
50 239.855953 -73.961841
51 238.936811 -73.887023
52 238.621490 -73.171441
53 240.771812 -73.847028
54 -16.798565 4.421919
55 -15.952454 3.911043
56 -14.337879 4.236691
57 -17.465204 3.610884
58 -17.270147 4.407737
59 -15.347879 3.256489
60 -18.197750 3.906086
A simpler approach consist in grouping the values where the percentage change is not greater than a given threshold (let's say 0.5):
df['Group'] = (df.A.pct_change().abs()>0.5).cumsum()
df.groupby('Group').agg(['mean', 'std'])
Output:
A B
mean std mean std
Group
0 3738.590934 30.769420 -1880.148905 7.582856
1 -344.724684 2.666137 22.496995 0.921008
2 24.790470 0.994361 -9.020824 0.977809
3 -3210.159806 11.646589 -2555.676749 8.810481
4 237.902230 2.439297 -72.998817 1.366350
5 -16.481411 1.341379 3.964407 0.430576
Note: I have only used the "A" column, since the "B" column appears to follow the same pattern of consecutive nearest values. You can check if the identified groups are the same between columns with:
grps = (df[['A','B']].pct_change().abs()>1).cumsum()
grps.A.eq(grps.B).all()
I would say that if you know the length of each group/index set you want then you can first subset the column and row with :
df['A'].iloc[0:11].mean()
Then figure out a way to find standard deviation.

Pandas randomly swap columns values per row

I want to train a binary classification ML model with some data that I have; something like this:
df
y ch1_g1 ch2_g1 ch3_g1 ch1_g2 ch2_g2 ch3_g2
0 20 89 62 23 3 74
1 51 64 19 2 83 0
0 14 58 2 71 31 48
1 32 28 2 30 92 91
1 51 36 51 66 15 14
...
My target (y) depends on three characteristics from two groups, however I have an imbalance in my data, a count of values of my y target reveals that I have more zeros than ones in a ratio of about 2.68. I correct this by looping each row and randomly swapping values from group 1 to group 2 and viceversa, like this:
for index,row in df.iterrows():
choice = np.random.choice([0,1])
if row['y'] != choice:
df.loc[index, 'y'] = choice
for column in df.columns[1:]:
key = column.replace('g1', 'g2') if 'g1' in column else column.replace('g2', 'g1')
df.loc[index, column] = row[key]
Doing this reduce the ratio to no more than 1.3, so I was wondering if there is a more direct aproach using pandas methods.
¿Anyone have an idea how to accomplish this?
Whether or not swapping columns solves class unbalance aside, I would swap the whole data set, and randomly choose between the original and the swapped:
# Step 1: swap the columns
df1 = pd.concat((df.filter(regex='[^(_g1)]$'),
df.filter(regex='_g1$')),
axis=1)
# Step 2: rename the columns
df1.columns = df.columns
# random choice
np.random.seed(1)
is_original = np.random.choice([True,False], size=len(df))
# concat to make new dataset
pd.concat((df[is_original],df1[~is_original]))
Output:
y ch1_g1 ch2_g1 ch3_g1 ch1_g2 ch2_g2 ch3_g2
2 0 14 58 2 71 31 48
3 1 32 28 2 30 92 91
0 0 23 3 74 20 89 62
1 1 2 83 0 51 64 19
4 1 66 15 14 51 36 51
Notice that row with indexes 1,4 have g1 swap with g2.

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