%Task1
%
%Calculates the velocity and the discharge at a point given the channel
%shape, roughness, and slope parameters.
%
%Author:  Wendy Bohon with significant help from David Raleigh, Feb. 26,
%2009.

% INPUTS: width             feet
%         depth             feet
%         roughness         feet
%         slope             unitless
%         verbose           1 or 0
% OUTPUT  discharge         ft^3/sec

%Roughness coefficient(n)=L^2 or just n^2 ; values off chart.
%Hydralic Radius (R)= (w*d)/(w+2d) ; which is A/P
%Q=discharge
%roughness parameter n [L^1/6]
%slope (s [dimensionless])
%hydralicRadius = area / wettedPerimeter;
%This is the equation that determines velocity (v). velocity =
%(1.49./roughness) .* hydralicRadius.^(2/3) .* slope.^(1/2)


function [discharge velocity hydralicRadius] = task1(width , depth , roughness , slope , verbose)

 
% if verbose you don't want to print out the statements
if verbose == 0
  %Wetted perimeter (P) = w+2d
  wettedPerimeter = width + 2 .* depth;
  %Hydralic Radius (R)= (w*d)/(w+2d) ; which is also A/P
  hydralicRadius = (width .* depth) ./ (width + 2 .* depth);
  % I have no idea where the unit of time comes from.
  velocity = (1.49./roughness) .* hydralicRadius.^(2/3) .* slope.^(1/2);
  % area
  channelArea = width .* depth;
  %area = width .* depth;
  discharge = velocity .* channelArea;
  
% if verbose does not equal 0 you want to print out all your pretty statements
elseif verbose ~= 0
  %Wetted perimeter (P) = w+2d
  wettedPerimeter = width + 2 .* depth
  %Hydralic Radius (R)= (w*d)/(w+2d) ; which is also A/P
  hydralicRadius = (width .* depth) ./ (width + 2 .* depth)
  % I have no idea where the unit of time comes from.
  velocity = (1.49./roughness) .* hydralicRadius.^(2/3) .* slope.^(1/2)
  % area
  channelArea = width .* depth
  %area = width .* depth;
  discharge = velocity .* channelArea
end