#1 Helicopter info collection, for design data base

All data here is fictional/imaginary.

Nothing in this belongs to me.

This is a record of work, for future use only.

Index

Name

Link

Disk loading

Main rotor diameter

Tail rotor diameter

Main rotor to tail rotor

Power

MTOW

Ceiling without ground effect

Engine

Payload

Max ascent speed

Service ceiling

Cruise speed

Endurance

Max speed

Fuselage length

kg/m2

m

m

m

W

kg

m

kg

m/s

m

m/s

hr

m/s

m

1

AeroDreams Chi-7

https://sites.google.com/site/stingrayslistofrotorcraft/aerodreams-chi-7

15.92356688

6

1.1

NA

74600

450

1800

Rotax 912

230

8

2500

36.11111111

10

52.77777778

7.15

Learning Neural networks 3

					-*- coding: utf-8 -*-

"""

@author: Balaji

"""

print('\n 18 March Program for a simple neural network, doing a forward pass with one layer')

print('\n 21 March Added provision for data generation for use in training.')

print('\n 21 March Formating input data as a matrix for faster multiplication with weights')

print('\n 22 March Initialise bias to 0, weights to very small ~0.01 random numbers, put computations inside a class')

import numpy as np

import matplotlib.pyplot as plt

class Layer_dense():

def __init__(self, num_pixels, num_neurons):

np.random.seed(1); #For repeatability

self.weights = np.random.randn(num_neurons ,num_pixels);

self.biases = np.random.randn(num_neurons ,1);

#self.output_beforeActivation = np.zeros((num_neurons,1));

def forward(self, inputs):

self.output_beforeActivation = np.dot(self.weights,inputs)+self.biases;

def applyReluActivation (self):

self.output_afterActivation = np.maximum(0,self.output_beforeActivation);

num_neurons = 4;

num_pixels = 5;

num_images = 10;

# Input data set properties

slope = np.tan(np.deg2rad(30));

intercept = 50;

print('\n Creating input data:')

np.random.seed(1); #For repeatability

inputs = np.zeros((num_pixels,num_images));

x = np.arange(0,num_pixels);

x = x.reshape((num_pixels,1));

for dataSet_iter in range(num_images):

inputs[:,dataSet_iter:dataSet_iter+1] = (slope*x+intercept) + (intercept*0.1)*(np.random.randn(x.size,1));

print('\n Plotting input data set :')

plt.plot(x,inputs,'o')

plt.xlabel('Pixel number')

plt.ylabel('Pixel value')

plt.title('Input data set')

plt.legend()

plt.show()

print('\n Create a dense layer, fully connected, of the class Layer_dense')

firstLayer = Layer_dense(num_pixels = num_pixels, num_neurons = num_neurons);

firstLayer.forward(inputs=inputs);

firstLayer.applyReluActivation();

print('\n Result = ')

print('\n Each column is result of the network per image, after activation')

print(firstLayer.output_afterActivation)

 

Learning neural networks 2

# -*- coding: utf-8 -*-
"""
@author: Balaji
"""
print('\n 18 March Program for a simple neural network, doing a forward pass with one layer')
print('\n 21 March Added provision for data generation for use in training.')
print('\n 21 March Formating input data as a matrix for faster multiplication with weights')

import numpy as np
import  matplotlib.pyplot as plt
num_neurons     = 4;
num_pixels      = 2;
num_images      = 3;
np.random.seed(1); #For repeatability
# Input data set properties
slope           = np.tan(np.deg2rad(30));
intercept       = 50;

print('\n Creating input data:')
inputs  = np.zeros((num_images,num_pixels));
x = np.arange(0,num_pixels);
for dataSet_iter in range(num_images):
    inputs[dataSet_iter,:] = (slope*x+intercept)+ intercept*0.2*(np.random.randn(1,x.size) );

print('\n Plotting input data set :')    
plt.plot(x,inputs.transpose(),'o')
plt.xlabel('Pixel number')
plt.ylabel('Pixel value')
plt.title('Input data set')
plt.legend()
plt.show()

print('\n Each row is a data set')
weights = np.random.randn(num_neurons ,num_pixels);
bias    = np.random.randn(num_neurons ,1);
results = np.zeros_like(bias)

print('\n Input = ')
print(inputs)

print('\n Weights = ')
print(weights)

print('\n Bias = ')
print(bias)

# Output computation in matrix format
results = np.dot(weights,inputs.transpose())+bias;

# Output  computation in loop method
for input_iter in inputs:
    for weight_iter,bias_iter,result_iter in zip(weights,bias,results):
        print('\n Input data set:')
        print(input_iter);
        print('\n is multiplied with weights')
        print(weight_iter)
        print('\n and added with bias')
        print(bias_iter)
        print('\n to give the result of neuron as')
        result_iter = input_iter.dot(weight_iter) + bias_iter;
        print(result_iter)

Learning neural networks 1

1 Simple forward pass of one layer neural network in Python, with numpy

 

# -*- coding: utf-8 -*-
"""
Created on Fri Mar 18 12:39:21 2022

@author: Balaji
"""

import numpy as np
num_neurons = 2;
num_inputs  = 3;
num_dataSets= 1;
print('\n Program for a simple neural network, doing a forward pass with one layer')
print('\n Each row is a data set')
inputs  = np.random.randn(num_dataSets,num_inputs);
weights = np.random.randn(num_neurons ,num_inputs);
bias    = np.random.randn(num_neurons ,1);
results = np.zeros_like(bias)

print('\n Input = ')
print(inputs)

print('\n Weights = ')
print(weights)

print('\n Bias = ')
print(bias)

for input_iter in inputs:
    for weight_iter,bias_iter,result_iter in zip(weights,bias,results):
        print('\n Input data set:')
        print(input_iter);
        print('\n is multiplied with weights')
        print(weight_iter)
        print('\n and added with bias')
        print(bias_iter)
        print('\n to give the result of neuron as')
        result_iter = input_iter.dot(weight_iter) + bias_iter;
        print(result_iter)