/************************************************************************/

//Please read the following comments about the prototypes of

// three function to implement in model.cpp for Programming #1A and #1B

/************************************************************************/

/************************************************************************/

//Calculate and return the probability of charGenerated actually typed

//given charOfTheState as the underlying cognitive state.

/************************************************************************/

double prCharGivenCharOfState(char charGenerated, char charOfTheState)

{ // KEYBOARD STATE

// CharGenerated = What we actually touched (typed)

// CharOfTheState = What we want to type in our mind (our cognitive state)

//**************************************************

//Replace the following with your own implementation

//**************************************************

return 0;

}

/************************************************************************/

//The following function implement part of the spelling model for

// spelling a word with sizeOfTable characters,

//This function

//(i) calculates for each cognitive state excluding the special states I and F,

// the probability of that cognitive state being the first cognitive state

// after the transition out of the special state I, and

//(ii) stores these probabilities in a prTable array of sizeOfTable elements.

//Note that the value of the parameter sizeOfTable should be

// exactly the number characters in the word.

/************************************************************************/

void getPrTableForPossibleInitialStates(double prTable[], int sizeOfTable)

{

//It is a word of sizeOfTable characters:

// i.e. the number of character states is sizeOfTable.

// let's index these characters from 0 to sizeOfTable-1.

//

//First calculate the sum of ratios of probabilities of

// going from the special I state into these character states.

//This allows you to calculate the scaling factor to determine the probabilities.

//Second, for each character state calculate the probability

// transitioning from the special I state into the character state.

//**************************************************

//Replace the following with your own implementation

//**************************************************

}

/************************************************************************/

//The following function implement part of the spelling model for

// spelling a word with sizeOfTable-1 characters,

// i.e. sizeOfTable should be 1 + the number characters in the word.

//This function

//(i) calculates for each actual cognitive state for a word

// (excluding the special I state but including the special F state),

// the probability of that cognitive state being the next cognitive state

// given currentState as the index of the current state in the word, and

//(ii) stores these probabilities in a transitionPrTable array of sizeOfTable elements.

//Note that the value of the parameter sizeOfTable should be

// 1 + the number characters in the word.

/************************************************************************/

void getPrTableForPossibleNextStates

(double transitionPrTable[], int sizeOfTable, int currentState)

{

//We are working on a word of sizeOfTable-1 characters:

// i.e. the number of character states is sizeOfTable-1.

//Index these character states from 0 to sizeOfTable-2 respectively, while

// the index of the special final state F is sizeOfTable-1.

//currentState is the index of the current state in the word

//First calculate the sum of ratios of probabilities of

// going from the current state into the other down-stream states down in word

// including all the down-stream character states and the

// special F final state.

//This allows you to calculate the scaling factor to determine the probabilities.

//Second, for each state (excluding the special I state)

// calculate the probability of

// transitioning from the current state into the character state

// and store the probability into the table.

//**************************************************

//Replace the following with your own implementation

//**************************************************

}

/************************************************************************/

// Please also read and check how these three function above

// are called in the following demo functions in demo.cpp

/************************************************************************/

/************************************************************************/

/************************************************************************/

void demoOfKeyboardModel()

{

cout << endl << endl

<< "*********************************************************" << endl

<< "Test the correctness of the keyboard model implementation, and" << endl

<< "show the probabilities of generating (touching) various characters" << endl

<< "when mentally you are in a state of trying to type something." << endl

<< "*********************************************************" << endl;

cout<<endl<<"Press space to continue."<<endl;

_getch();

char asciiMap[] = "abcdefghijklmnopqrstuvwxyz";

for (int i=0; i< 26; i++)

{double prSum;

prSum = 0;

cout << "Probability distribution regarding " << endl

<< "all possible resulting characters when trying to type "

<< asciiMap[i] << endl;

for (int j=0; j< 26; j++)

{

cout << '\t'

<< "Pr[Char=" << asciiMap[j] << "|State=" << asciiMap[i] << "]="

<< prCharGivenCharOfState(asciiMap[j], asciiMap[i]) << endl;

prSum += prCharGivenCharOfState(asciiMap[j], asciiMap[i]);

}

cout << "The sum of probability distribution over " << endl

<< "all possible resulting characters when trying to type \'" << endl

<< asciiMap[i]

<< "\' has been verified as "

<< prSum << endl << endl;

cout<<endl<<"Press space to continue."<<endl;

_getch();

}

cout << endl << endl ;

}

/************************************************************************/

/************************************************************************/

void demoInitialProbability()

{

cout << endl << endl

<< "*********************************************************" << endl

<< "Consider the 3-character word \"his\" "<< endl

<< "Demonstrate the probability distribution over the possible cognitive states" << endl

<< "after the transition from the special initial state I." << endl

<< "*********************************************************" << endl;

cout<<endl<<"Press space to continue."<<endl;

_getch();

int sizeOfTable = strlen("his");

int currentState;

double prSum = 0;

double initialPrTable[3];

getPrTableForPossibleInitialStates(initialPrTable,3);

string word = "his";

for (currentState=0; currentState < sizeOfTable; currentState++)

{ cout << '\t'

<< "Pr[State=" << word[currentState] << "]="

<< initialPrTable[currentState] << endl;

prSum += initialPrTable[currentState];

}

cout << "The sum of probability distribution over " << endl

<< "all possible states after the first transition" << endl

<< "has been verified as " << prSum << endl << endl;

cout<<endl<<"Press space to continue." << endl;

_getch();

}

/************************************************************************/

/************************************************************************/

void demoTransitionProbability()

{

cout << endl << endl

<< "*********************************************************" << endl

<< "Consider the 3-character word \"his\" "<< endl

<< "Show the transition probabilities when spelling the word." << endl

<< "*********************************************************" << endl

<< "Demonstrate transition probabilities from current state to the next state." << endl

<< "We use special character \'_\' to represent the special final state F." << endl

<< "*********************************************************" << endl;

cout<<endl<<"Press space to continue."<<endl;

_getch();

//One more example

int sizeOfSpace = strlen("his")+1;

string word="his_";

for (int currentState=0; currentState< sizeOfSpace-1; currentState++)

{ double prSum, transitionPrTable[4];

cout << "Probability distribution over " << endl

<< "all possible next states given that the current state is "

<< word[currentState] << endl;

prSum = 0;

//nextStatePrTableGivenCurrentState(currentState,transitionPrTable,6);

getPrTableForPossibleNextStates

(transitionPrTable, 4, currentState);

for (int nextState=0; nextState< sizeOfSpace; nextState++)

{ cout << '\t'

<< "Pr[NextState=" << word[nextState] << "|CurrentState=" << word[currentState] << "]="

<< transitionPrTable[nextState] << endl;

prSum += transitionPrTable[nextState];

}

cout << "The sum of probabilities over " << endl

<< "all possible next states given that CurrentState="

<< word[currentState] << endl

<< "is verified as "

<< prSum << endl << endl;

cout<<endl<<"Press space to continue."<<endl;

_getch();

}

//One more example

cout << endl << endl

<< "*********************************************************" << endl

<< "Consider the 5-character word \"right\" "<< endl

<< "Show the transition probabilities when spelling the word." << endl

<< "*********************************************************" << endl

<< "Demonstrate transition probabilities from current state to the next state." << endl

<< "We use special character \'_\' to represent the special final state F." << endl

<< "*********************************************************" << endl;

cout<<endl<<"Press space to continue."<<endl;

_getch();

sizeOfSpace = strlen("right")+1;

word="right_";

for (int currentState=0; currentState< sizeOfSpace-1; currentState++)

{ double prSum, transitionPrTable[6];

cout << "Probability distribution over " << endl

<< "all possible next states given that the current state is "

<< word[currentState] << endl;

prSum = 0;

//nextStatePrTableGivenCurrentState(currentState,transitionPrTable,6);

getPrTableForPossibleNextStates

(transitionPrTable, 6, currentState);

for (int nextState=0; nextState< sizeOfSpace; nextState++)

{ cout << '\t'

<< "Pr[NextState=" << word[nextState] << "|CurrentState=" << word[currentState] << "]="

<< transitionPrTable[nextState] << endl;

prSum += transitionPrTable[nextState];

}

cout << "The sum of probabilities over " << endl

<< "all possible next states given that CurrentState="

<< word[currentState] << endl

<< "is verified as "

<< prSum << endl << endl;

cout<<endl<<"Press space to continue."<<endl;

_getch();

}

}