How to get array after adding a number to specific data of that array?

Question

import numpy as np 
import xlrd
import xlwt

wb = xlrd.open_workbook('Scatter plot.xlsx')
workbook = xlwt.Workbook() 

sheet = workbook.add_sheet("Sheet1")

sh1 = wb.sheet_by_name('T180')
sh2=wb.sheet_by_name("T181")

x= np.array([sh1.col_values(1, start_rowx=51, end_rowx=315)])
y= np.array([sh1.col_values(2, start_rowx=51, end_rowx=315)])

x1= np.array([sh2.col_values(1, start_rowx=50, end_rowx=298)])
y1= np.array([sh2.col_values(2, start_rowx=50, end_rowx=298)])

condition = [(x1<=1000) & (x1>=0) ]
condition1 = [(y1<=1000) & (y1>=0) ]

x_prime=x1[condition]-150
y_prime= y[condition1]+20

plt.plot(x,y, "ro", label="T180")
plt.plot(x_prime,y_prime,"gs")
plt.show()

I want to subtract 150 from the values less than 1000 of x1 array and finally I need all values (subtracted+remaining). But with this code I got only the values that are less than 1000. But I need both (less than 1000+ greater than 1000). But greater than 1000 values will be unchanged. How can I will do this. As you can see there 248 elements in x1 array so after subtraction I will need 248 element as x_prime. Same as for y. Thanks in advance for your kind co-operation.

can you upload your Excel file somewhere and post here a link? It would help us to code and test solutions... — MaxU - stand with Ukraine
– MaxU - stand with Ukraine, Commented Sep 22, 2016 at 8:29
I cannot upload it, I did not find anyway to upload this file. What can I do? Thanks for your kind concern.@MaxU — Quazi Nizam
– Quazi Nizam, Commented Sep 22, 2016 at 8:34

MaxU - stand with Ukraine · Accepted Answer · 2016-09-25 08:13:00Z

1

Here is a Pandas solution:

import matplotlib
import matplotlib.pyplot as plt
import pandas as pd

matplotlib.style.use('ggplot')

fn = r'/path/to/ExcelFile.xlsx'
sheetname = 'T181'
df = pd.read_excel(fn, sheetname=sheetname, skiprows=47, parse_cols='B:C').dropna(how='any')

# customize X-values
df.ix[df.eval('0 <= GrvX <= 1000'), 'GrvX'] -= 150
df.ix[df.eval('2500 < GrvX <= 3000'), 'GrvX'] += 50
df.ix[df.eval('3000 < GrvX'), 'GrvX'] += 30

# customize Y-values
df.ix[df.eval('0 <= GrvY <= 1000'), 'GrvX'] += 20

df.plot.scatter(x='GrvX', y='GrvY', marker='s', s=30, label=sheetname, figsize=(14,12))

plt.show()

edited Sep 25, 2016 at 8:13

answered Sep 22, 2016 at 17:43

MaxU - stand with Ukraine

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11 Comments

Quazi Nizam Over a year ago

Thank you bro. It shows error in fn. What to do? @MaxU

MaxU - stand with Ukraine Over a year ago

@QuaziNizam, sorry, fn - is a filename (including a path) - it's got lost. I've corrected my answer...

Quazi Nizam Over a year ago

Thanks. One more problem, I want figure like this filedropper.com/figure2_1 , but according to your code I found like this: filedropper.com/figure3 How to solve?@MaxU

Quazi Nizam Over a year ago

Thanks. Its working now. If I want more condition like -150 for <1000, and add 50 for values >2500,add 30 for >3000 of x1 (same as y1) what can I do? @MaxU

MaxU - stand with Ukraine Over a year ago

@QuaziNizam, you can do it similar to df.ix[df.eval('0 <= GrvX <= 1000'), 'GrvX'] -= 150...

|

eistaa · Accepted Answer · 2016-09-22 09:35:37Z

1

You can use numpy.place to modify arrays where a logic expression holds. For complex logic expressions on the array there are the logic functions that combines boolean arrays.

E.g.:

A = np.array([1, 2, 3, 4, 5, 6, 7, 8, 9, 10])
np.place(A, np.logical_and(A > 1, A <= 8), A-10)

will subtract 10 from every element of A that is > 1 and <= 8. After this A will be

array([ 1, -9, -8, -7, -6, -5, -4, -3,  9, 10])

edited Sep 22, 2016 at 9:35

answered Sep 22, 2016 at 9:25

eistaa

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5 Comments

Quazi Nizam Over a year ago

"ValueError: object too deep for desired array" it shows this kind of error for the following code: z=np.place(x1, np.logical_and(x1 > 1, x1 <= 1000), x1-150) print z @eistaa

eistaa Over a year ago

@QuaziNizam I think the error comes because your x1 is multidimensional. When you construct x, y, x1, and y1 you have [ ] brackets around the col_values expression, this makes a list containing a slice, while you only want the slice. Try removing those brackets.

Quazi Nizam Over a year ago

Thanks. Its working now. If I want more condition like -150 for <1000, and add 50 for values >25000,add 30 for >3000 of x1 (same as y1) what can I do?

eistaa Over a year ago

@QuaziNizam use multiple place statements

Quazi Nizam Over a year ago

Sorry I cannot understand. Would you please just show me the code as example. Thanks for your kind help. @eistaa

Sayali Sonawane · Accepted Answer · 2016-09-22 09:38:13Z

0

import numpy as np 
#random initialization
x1=np.random.randint(1,high=3000, size=10)

x_prime=x1.tolist()

for i in range(len(x_prime)):
    if(x_prime[i]<=1000 and x_prime[i]>=0): 
        x_prime[i]=x_prime[i]-150

x_prime=np.asarray(x_prime)

Answer:

x1
Out[151]: array([2285, 2243, 1716,  632, 2489, 2837, 2324, 2154,  562, 2508])

x_prime
Out[152]: array([2285, 2243, 1716,  482, 2489, 2837, 2324, 2154,  412, 2508])

answered Sep 22, 2016 at 9:38

Sayali Sonawane

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2 Comments

Quazi Nizam Over a year ago

Thanks, but it shows same result for x1 and x_prime. @ Sayali Sonawane

Sayali Sonawane Over a year ago

you will get same results, if you won't convert it into list first. This is why, I have converted it into list first. Then perform operations and convert back to array.

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