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@iemcd iemcd/boatmath.m
Created Aug 17, 2019

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% Estimating the length & beam of boats from their tonnage.
% Ian McDougall
% 25 July 2019
clear all, close all, nfig=0;
% The Thames Measurement (TM) estimates the tonnage of a ship given its length (LOA) and beam in feet. It is intended for yachts.
function tons = TM(LOA,beam)
tons = ((LOA - beam).*beam.^2)/188;
endfunction
% The Builder's Old Measurement (BOM) estamtes the tonnage of a ship given its LOA and beam in feet. It is older than the Thames measurement.
function tons = BOM(LOA,beam)
tons = ((LOA - 0.6*beam).*beam.^2)/188;
endfunction
% This rule-of-thumb (ROT) estimates the beam in feet, given the LOA.
function beam = ROT(LOA)
beam = LOA.^(2/3) +1;
endfunction
% The hull speed is an early boat limitation in knots, given LWL in feet (length at the waterline)
function vhull = hull(LWL)
vhull = 1.34.*LWL.^0.5;
endfunction
init_ft = 10;
tons = 0;
for i = 1:10
tons = i
length = fzero(@(LOA) BOM(LOA,ROT(LOA))-i,init_ft)
vhull = hull(length)
init_ft = length;
endfor
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