My requirement is to graph (scatter graph) data from 2 arrays. I can now connect the data from the array and use it on the chart. My question is, how do I set the graph's X- and Y- axes to show consistency in their intervals?
For example, I have points from X = {1, 3, 4, 6, 8, 9} and Y = {7, 10, 11, 15, 18, 19}. What I would like to see is that these points are graphed in a scatter manner, but, the intervals for x-axis should be (intervals of) 2 up to 10 (such that it will show 0, 2, 4, 6, 8, 10 on x-axis) and intervals of 5 for the y-axis (such that it will show 5, 10, 15, 20 on y-axis). What code/property should I use/manipulate?
ADDED PART:
I currently have this data:
x_column = {12, 24, 1, 7, 29, 28, 25, 24, 15, 19}
y_column = {3, 5, 8, 3, 3, 3, 3, 3, 19, 15}
each y_column element is a pair of each respective x_column element
Now, I want MyChart to display a scatter graph of the x_column and y_column data in such a way that the x-axis will show 5, 10, 15, 20, 25, 30 and the y-axis will show 2, 4, 6, 8, 10, 12, 14, 16, 18, 20.
My current code is:
' add points
MyChart.Series("Scatter Plot").Points.DataBindXY(x_Column, y_Column)
The code above only adds points.
Try:
Chart1.ChartAreas("Default").AxisX.Interval = 2
Chart1.ChartAreas("Default").AxisY.Interval = 5
Related
import numpy as np
data = np.array([[10, 20, 30, 40, 50, 60, 70, 80, 90],
[2, 7, 8, 9, 10, 11],
[3, 12, 13, 14, 15, 16],
[4, 3, 4, 5, 6, 7, 10, 12]],dtype=object)
target = data[:,0]
It has this error.
IndexError Traceback (most recent call last)
Input In \[82\], in \<cell line: 9\>()
data = np.array(\[\[10, 20, 30, 40, 50, 60, 70, 80, 90\],
\[2, 7, 8, 9, 10, 11\],
\[3, 12, 13, 14, 15, 16\],
\[4, 3, 4, 5, 6, 7, 10,12\]\],dtype=object)
# Define the target data ----\> 9 target = data\[:,0\]
IndexError: too many indices for array: array is 1-dimensional, but 2 were indexed
May I know how to fix it, please? I mean do not change the elements in the data. Many thanks. I made the matrix in the same size and the error message was gone. But I have the data with variable size.
You have a array of objects, so you can't use indexing on axis=1 as there is none (data.shape -> (4,)).
Use a list comprehension:
out = np.array([a[0] for a in data])
Output: array([10, 2, 3, 4])
val primes = generateSequence(2 to generateSequence(3) {it + 2}) {
val currSeq = it.second.iterator()
val nextPrime = currSeq.next()
nextPrime to currSeq.asSequence().filter { it % nextPrime != 0}
}.map {it.first}
println(primes.take(10).toList()) // prints [2, 3, 5, 7, 11, 13, 17, 19, 23, 29]
I tried to understand this function about how it works, but not easy to me.
Could someone explain how it works? Thanks.
It generates an infinite sequence of primes using the "Sieve of Eratosthenes" (see here: https://en.wikipedia.org/wiki/Sieve_of_Eratosthenes).
This implementation uses a sequence of pairs to do this. The first element of every pair is the current prime, and the second element is a sequence of integers larger than that prime which is not divisible by any previous prime.
It starts with the pair 2 to [3, 5, 7, 9, 11, 13, 15, 17, ...], which is given by 2 to generateSequence(3) { it + 2 }.
Using this pair, we create the next pair of the sequence by taking the first element of the sequence (which is now 3), and then removing all numbers divisible by 3 from the sequence (removing 9, 15, 21 and so on). This gives us this pair: 3 to [5, 7, 11, 13, 17, ...]. Repeating this pattern will give us all primes.
After creating a sequence of pairs like this, we are finally doing .map { it.first } to pick only the actual primes, and not the inner sequences.
The sequence of pairs will evolve like this:
2 to [3, 5, 7, 9, 11, 13, 15, 17, 19, 21, 23, 25, 27, 29, ...]
3 to [5, 7, 11, 13, 17, 19, 23, 25, 29, ...]
5 to [7, 11, 13, 17, 19, 23, 29, ...]
7 to [11, 13, 17, 19, 23, 29, ...]
11 to [13, 17, 19, 23, 29, ...]
13 to [17, 19, 23, 29, ...]
// and so on
Problem:
I have a list of ~108 dictionaries named list_of_dictionary and I would like to use Matplotlib to generate line graphs.
The dictionaries have the following format (this is one of 108):
{'price': [59990,
59890,
60990,
62990,
59990,
59690],
'car': '2014 Land Rover Range Rover Sport',
'datetime': [datetime.datetime(2020, 1, 22, 11, 19, 26),
datetime.datetime(2020, 1, 23, 13, 12, 33),
datetime.datetime(2020, 1, 28, 12, 39, 24),
datetime.datetime(2020, 1, 29, 18, 39, 36),
datetime.datetime(2020, 1, 30, 18, 41, 31),
datetime.datetime(2020, 2, 1, 12, 39, 7)]
}
Understanding the dictionary:
The car 2014 Land Rover Range Rover Sport was priced at:
59990 on datetime.datetime(2020, 1, 22, 11, 19, 26)
59890 on datetime.datetime(2020, 1, 23, 13, 12, 33)
60990 on datetime.datetime(2020, 1, 28, 12, 39, 24)
62990 on datetime.datetime(2020, 1, 29, 18, 39, 36)
59990 on datetime.datetime(2020, 1, 30, 18, 41, 31)
59690 on datetime.datetime(2020, 2, 1, 12, 39, 7)
Question:
With this structure how could one create mini-graphs with matplotlib (say 11 rows x 10 columns)?
Where each mini-graph will have:
the title of the graph frome car
x-axis from the datetime
y-axis from the price
What I have tried:
df = pd.DataFrame(list_of_dictionary)
df = df.set_index('datetime')
print(df)
I don't know what to do thereafter...
Relevant Research:
Plotting a column containing lists using Pandas
Pandas column of lists, create a row for each list element
I've read these multiple times, but the more I read it, the more confused I get :(.
I don't know if it's sensible to try and plot that many plots on a figure. You'll have to make some choices to be able to fit all the axes decorations on the page (titles, axes labels, tick labels, etc...).
but the basic idea would be this:
car_data = [{'price': [59990,
59890,
60990,
62990,
59990,
59690],
'car': '2014 Land Rover Range Rover Sport',
'datetime': [datetime.datetime(2020, 1, 22, 11, 19, 26),
datetime.datetime(2020, 1, 23, 13, 12, 33),
datetime.datetime(2020, 1, 28, 12, 39, 24),
datetime.datetime(2020, 1, 29, 18, 39, 36),
datetime.datetime(2020, 1, 30, 18, 41, 31),
datetime.datetime(2020, 2, 1, 12, 39, 7)]
}]*108
fig, axs = plt.subplots(11,10, figsize=(20,22)) # adjust figsize as you please
for car,ax in zip(car_data, axs.flat):
ax.plot(car["datetime"], car['price'], '-')
ax.set_title(car['car'])
Ideally, all your axes could share the same x and y axes so you could have the labels only on the left-most and bottom-most axes. This is taken care of automatically if you add sharex=True and sharey=True to subplots():
fig, axs = plt.subplots(11,10, figsize=(20,22), sharex=True, sharey=True) # adjust figsize as you please
I have a numpy array (inputs) of shape (30,1). I want to insert 31st value (eg. x = 2). Trying to use the np.insert function but it is giving me out of bounds error.
np.insert(inputs,b+1,x)
IndexError: index 31 is out of bounds for axis 0 with size 30
Short answer: you need to insert it at index b, not b+1.
The index you pass to np.insert(..) [numpy-doc], is the one where the element should be added. If you insert it at index 30, then it will be positioned last. Note that indexes are zero-based. So if you have an array with 30 elements, then the last index is 29. If you thus insert this at index 30, we get:
>>> a
array([ 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16,
17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29])
>>> np.insert(a,30,42)
array([ 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16,
17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 42])
I'm developing a pythong script where I receive angular measurements from a motor which has a low resolution encoder attached to it. The data I get from the motor has a very low resolution (about 5 degrees division in between measurments). This is an example of the sensor output whilst it is rotating with a constant speed (in degrees):
sensor output = ([5, 5, 5, 5, 5, 10, 10, 10, 10 ,10, 15, 15, 20, 20, 20, 20, 25, 25, 30, 30, 30, 30, 30, 35, 35....])
As you can see, some of these measurements are repeating themselves.
From these measurements, I would like to interpolate in order to get the measurements in between the 1D data-points. For instance, if I at time k receive the angular measurement theta=5 and in the next instance at t=k+1 also receive a measurement of theta=5, I would like to compute an estimate that would be something like theta = 5+(1/5).
I have also been considering using some sort of predictive filtering, but I'm not sure which one to apply if that is even applicable in this case (e.g. Kalman filtering). The estimated output should be in a linear form since the motor is rotating with a constast angular velocity.
I have tried using numpy.linspace in order to acheive what I want, but cannot seem to get it to work the way I want:
# Interpolate for every 'theta_div' values in angle received through
# modbus
for k in range(np.size(rx)):
y = T.readSensorData() # take measurement (call read sensor function)
fp = np.linspace(y, y+1, num=theta_div)
for n in range(theta_div):
if k % 6 == 0:
if not y == fp[n]:
z = fp[n]
else:
z = y
print(z)
So for the sensor readings: ([5, 5, 5, 5, 5, 10, 10, 10, 10 ,10, 15, 15, 20, 20, 20, 20, 25, 25, 30, 30, 30, 30, 30, 35, 35....]) # each element at time=k0...kn
I would like the output to be something similar to:
theta = ([5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 17.5, 20...])
So in short, I need some sort of prediction and then update the value with the actual reading from the sensor, similar to the procedure in a Kalman filter.
why dont just make a linear fit?
import numpy as np
import matplotlib.pyplot as plt
messurements = np.array([5, 5, 5, 5, 5, 10, 10, 10, 10 ,10, 15, 15, 20, 20, 20, 20, 25, 25, 30, 30, 30, 30, 30, 35, 35])
time_array = np.arange(messurements.shape[0])
fitparms = np.polyfit(time_array,messurements,1)
def line(x,a,b):
return a*x +b
better_time_array = np.linspace(0,np.max(time_array))
plt.plot(time_array,messurements)
plt.plot(better_time_array,line(better_time_array,fitparms[0],fitparms[1]))