{"id":1035,"date":"2023-04-14T05:38:28","date_gmt":"2023-04-14T09:38:28","guid":{"rendered":"https:\/\/blogs.mathworks.com\/matlab\/?p=1035"},"modified":"2023-04-14T12:25:48","modified_gmt":"2023-04-14T16:25:48","slug":"celebrating-springtime-the-matlab-daffodil","status":"publish","type":"post","link":"https:\/\/blogs.mathworks.com\/matlab\/2023\/04\/14\/celebrating-springtime-the-matlab-daffodil\/","title":{"rendered":"Celebrating springtime: The MATLAB Daffodil"},"content":{"rendered":"
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\"\"<\/div>\r\n
Although not the earliest to appear here in the UK, Daffodils are the flowers that, for me at least, scream \"Spring has sprung.\" The brief but glorious Daffodil season is coming to an end in my area of the world so I was delighted by the following piece of MATLAB code written by MathWorker Eric Ludlam which allows me to extend the season for a little while longer.<\/div>\r\n
The use of some surprisingly little-known functions that I've written about before<\/a>: cospi<\/span><\/a> and sinpi<\/span><\/a> also make me happy!<\/div>\r\n
Enjoy!<\/div>\r\n
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%% Colors & Sizes<\/span><\/span><\/div>\r\n<\/div>\r\n
\r\n
pc = '#faca00'<\/span>; % petal color<\/span><\/span><\/div>\r\n<\/div>\r\n
\r\n
sc = '#97b580'<\/span>; % stem color<\/span><\/span><\/div>\r\n<\/div>\r\n
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np = 6; % number of petals.<\/span><\/span><\/div>\r\n<\/div>\r\n
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tr = .23; % Radius of trumpet<\/span><\/span><\/div>\r\n<\/div>\r\n
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nruf = 10; % number of trumpet ruffles<\/span><\/span><\/div>\r\n<\/div>\r\n
\r\n
sruf = .03; % size of trumpet ruffles<\/span><\/span><\/div>\r\n<\/div>\r\n
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sr = .05; % radius of the stem<\/span><\/span><\/div>\r\n<\/div>\r\n
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<\/div>\r\n<\/div>\r\n
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%% Unit circle arrays<\/span><\/span><\/div>\r\n<\/div>\r\n
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n = np*50+1; % Theta resolution<\/span><\/span><\/div>\r\n<\/div>\r\n
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theta = linspace(0,2,n);<\/span><\/div>\r\n<\/div>\r\n
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nr = 20; % Radus resolution<\/span><\/span><\/div>\r\n<\/div>\r\n
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r = linspace(0,1,nr)';<\/span><\/div>\r\n<\/div>\r\n
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<\/div>\r\n<\/div>\r\n
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%% Petals<\/span><\/span><\/div>\r\n<\/div>\r\n
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PR = r .* ((1-abs(1-mod(theta*np, 2)))\/2+.5);<\/span><\/div>\r\n<\/div>\r\n
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PX = PR .* cospi(theta);<\/span><\/div>\r\n<\/div>\r\n
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PY = PR .* sinpi(theta);<\/span><\/div>\r\n<\/div>\r\n
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PZ = r.^3*.05+hypot(PX,PY)*.2;<\/span><\/div>\r\n<\/div>\r\n
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% Face our flower sideways by swapping Y&Z<\/span><\/span><\/div>\r\n<\/div>\r\n
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surf(PX,PZ,PY,[],'FaceColor'<\/span>,pc,'EdgeColor'<\/span>,'none'<\/span>);<\/span><\/div>\r\n<\/div>\r\n
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<\/div>\r\n<\/div>\r\n
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%% Trumpet<\/span><\/span><\/div>\r\n<\/div>\r\n
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flute = flip(1-r*.3);<\/span><\/div>\r\n<\/div>\r\n
\r\n
ruffle = ((cospi(theta*nruf)+2)*sruf).*(linspace(0,1,nr)'.^5);<\/span><\/div>\r\n<\/div>\r\n
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ruffle2 = ((cospi(theta*nruf*3)+2)*sruf\/3).*(linspace(0,1,nr)'.^9);<\/span><\/div>\r\n<\/div>\r\n
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TR = tr*flute + ruffle + ruffle2;<\/span><\/div>\r\n<\/div>\r\n
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surface(TR.*cospi(theta),r*tr*3.2,TR.*sinpi(theta),'FaceColor'<\/span>,pc,'EdgeColor'<\/span>,'none'<\/span>);<\/span><\/div>\r\n<\/div>\r\n
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<\/div>\r\n<\/div>\r\n
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%% Stem<\/span><\/span><\/div>\r\n<\/div>\r\n
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SR = sr .* ones(nr,1);<\/span><\/div>\r\n<\/div>\r\n
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surface(SR.*cospi(theta),SR.*sinpi(theta)-sr,r*-2.*ones(1,n),'FaceColor'<\/span>,sc,'EdgeColor'<\/span>,'none'<\/span>);<\/span><\/div>\r\n<\/div>\r\n
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<\/div>\r\n<\/div>\r\n
\r\n
%% Configure Axes & Lighting<\/span><\/span><\/div>\r\n<\/div>\r\n
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set(gca,'YDir'<\/span>,'reverse'<\/span>,'Projection'<\/span>,'perspective'<\/span>,'Visible'<\/span>,'off'<\/span>,'DataAspectRatio'<\/span>,[1 1 1])<\/span><\/div>\r\n<\/div>\r\n
\r\n
light('Position'<\/span>,[.5 .5 2],'Color'<\/span>,'w'<\/span>);<\/span><\/div>\r\n<\/div>\r\n
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lighting g<\/span><\/span><\/div>\r\n<\/div>\r\n
\r\n
material([.8 .9 .2 2 .4])<\/span><\/div>\r\n<\/div>\r\n
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view([-40 20]);<\/span><\/div>\r\n<\/div>\r\n
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<\/div>\r\n
<\/div>\r\n
<\/div>\r\n
<\/div>\r\n<\/div>\r\n<\/div>\r\n<\/div>\r\n<\/div>\r\n
Perhaps try playing around with the code a little to come up with some variations.<\/div>\r\n<\/div>","protected":false},"excerpt":{"rendered":"
<\/div>

\r\n\r\nAlthough not the earliest to appear here in the UK, Daffodils are the flowers that, for me at least, scream \"Spring has sprung.\" The brief but glorious Daffodil season is coming to an end in my... read more >><\/a><\/p>","protected":false},"author":176,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":[],"categories":[63,60],"tags":[],"_links":{"self":[{"href":"https:\/\/blogs.mathworks.com\/matlab\/wp-json\/wp\/v2\/posts\/1035"}],"collection":[{"href":"https:\/\/blogs.mathworks.com\/matlab\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/blogs.mathworks.com\/matlab\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/blogs.mathworks.com\/matlab\/wp-json\/wp\/v2\/users\/176"}],"replies":[{"embeddable":true,"href":"https:\/\/blogs.mathworks.com\/matlab\/wp-json\/wp\/v2\/comments?post=1035"}],"version-history":[{"count":3,"href":"https:\/\/blogs.mathworks.com\/matlab\/wp-json\/wp\/v2\/posts\/1035\/revisions"}],"predecessor-version":[{"id":1050,"href":"https:\/\/blogs.mathworks.com\/matlab\/wp-json\/wp\/v2\/posts\/1035\/revisions\/1050"}],"wp:attachment":[{"href":"https:\/\/blogs.mathworks.com\/matlab\/wp-json\/wp\/v2\/media?parent=1035"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/blogs.mathworks.com\/matlab\/wp-json\/wp\/v2\/categories?post=1035"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/blogs.mathworks.com\/matlab\/wp-json\/wp\/v2\/tags?post=1035"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}