I have the following function, well it is the formula of the normal distribution and my goal is to graph it using the GraphView library. Well, I have the following:
code kotlin
class ExampleActivity : AppCompatActivity() {
lateinit var series1: LineGraphSeries<DataPoint>
override fun onCreate(savedInstanceState: Bundle?) {
super.onCreate(savedInstanceState)
setContentView(R.layout.activity_example)
series1 = LineGraphSeries<DataPoint>()
val media = 8.0
val sd = 2.0
fun linspace(start: Double, stop: Double, num: Int) = Array(num) { start + it * ((stop - start) / (num - 1)) }
val x1 = linspace(media - 3*sd, media + 3*sd, 10)
val normal = NormalDistribution(media,sd)
for (i in x1){
val y = normal.cumulativeProbability(i)
series1.appendData(DataPoint(i,y),false,x1.size)
}
plot.viewport.isXAxisBoundsManual = true
plot.viewport.setMaxX(20.0)
plot.viewport.isYAxisBoundsManual = true
plot.viewport.setMaxY(2.0)
//plot.viewport.isScalable = true
plot.addSeries(series1)
}
}
this is very strange, in python I used the same and the result is more complete, I show you.
code python
import matplotlib.pyplot as plt
import numpy as np
import scipy.stats as stats
import math
mu = 8
sigma = 2
x = np.linspace(mu - 3*sigma, mu + 3*sigma, 10)
print(np.linspace(mu - 3*sigma, mu + 3*sigma, 10))
plt.plot(x, stats.norm.pdf(x, mu, sigma))
plt.show()
Info
code kotlin
val x1 = linspace(media - 3*sd, media + 3*sd, 10)
==
code Python
x = np.linspace(mu - 3*sigma, mu + 3*sigma, 10)
Can you help me please, what do I need to add?
It looks like the python example is plotting the .pdf
"probability density function" while the kotlin example is plotting the .cumulativeProbability
which is essentially the integral of the PDF. Most likely you'll want to use the .density
method instead.