{"id":375,"date":"2014-04-02T04:16:33","date_gmt":"2014-04-02T04:16:33","guid":{"rendered":"http:\/\/ahay.org\/blog\/?p=375"},"modified":"2015-08-30T04:44:56","modified_gmt":"2015-08-30T04:44:56","slug":"program-of-the-month-sfcostaper","status":"publish","type":"post","link":"https:\/\/ahay.org\/blog\/2014\/04\/02\/program-of-the-month-sfcostaper\/","title":{"rendered":"Program of the month: sfcostaper"},"content":{"rendered":"<p><a href=\"\/RSF\/sfcostaper.html\">sfcostaper<\/a> applies cosine tapering to the edges of the input data. <\/p>\n<p>Cosine tapering amounts to multiplying the edges by<br \/>\n$$\\sin^2\\left(\\frac{\\pi\\,x}{2}\\right) = \\frac{1+\\cos{(\\pi\\,x)}}{2}$$,<br \/>\nwhere $x$ is the relative distance from the start of the taper. <\/p>\n<p><strong>sfcostaper<\/strong> works in N dimensions, the size of the taper in <strong>#<\/strong>th dimension in samples is specified by <strong>nw#=<\/strong>. In the following example from <a href=\"\/RSF\/book\/gee\/ajt\/igrad1.html\">gee\/ajt\/igrad1<\/a> the images are tapered at both edges by specifying <strong>nw1=50 nw2=50<\/strong>. <\/p>\n<p><img decoding=\"async\" src=\"\/RSF\/book\/gee\/ajt\/igrad1\/Fig\/stangrad.png\" alt=\"\" title=\"\" \/><\/p>\n<h3 id=\"10previousprogramsofthemonth\">10 previous programs of the month:<\/h3>\n<ul>\n<li><a href=\"\/blog\/2014\/03\/11\/program-of-the-month-sflpad\/\">sflpad<\/a><\/li>\n<li><a href=\"\/blog\/2014\/02\/06\/program-of-the-month-sfdipfilter\/\">sfdipfilter<\/a><\/li>\n<li><a href=\"\/blog\/2014\/01\/09\/program-of-the-month-sfinttest1\/\">sfinttest1<\/a><\/li>\n<li><a href=\"\/blog\/2013\/12\/01\/program-of-the-month-sfcausint\/\">sfcausint<\/a><\/li>\n<li><a href=\"\/blog\/2013\/11\/03\/program-of-the-month-sfremap1\/\">sfremap1<\/a><\/li>\n<li><a href=\"\/blog\/2013\/10\/03\/program-of-the-month-sfunif2\/\">sfunif2<\/a><\/li>\n<li><a href=\"\/blog\/2013\/09\/14\/program-of-the-month-sfpatch\/\">sfpatch<\/a><\/li>\n<li><a href=\"\/blog\/2013\/08\/02\/program-of-the-month-sfai2refl\/\">sfai2refl<\/a><\/li>\n<li><a href=\"\/blog\/2013\/07\/01\/program-of-the-month-sftime2depth\/\">sftime2depth<\/a><\/li>\n<li><a href=\"\/blog\/2013\/06\/12\/program-of-the-month-sfwiggle\/\">sfwiggle<\/a><\/li>\n<\/ul>\n","protected":false},"excerpt":{"rendered":"<p>sfcostaper applies cosine tapering to the edges of the input data. Cosine tapering amounts to multiplying the edges by $$\\sin^2\\left(\\frac{\\pi\\,x}{2}\\right) = \\frac{1+\\cos{(\\pi\\,x)}}{2}$$, where $x$ is the relative distance from the start of the taper. sfcostaper works in N dimensions, the size of the taper in #th dimension in samples is specified by nw#=. In the [&hellip;]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_import_markdown_pro_load_document_selector":0,"_import_markdown_pro_submit_text_textarea":"","activitypub_content_warning":"","activitypub_content_visibility":"local","activitypub_max_image_attachments":4,"activitypub_interaction_policy_quote":"","footnotes":""},"categories":[3],"tags":[],"class_list":["post-375","post","type-post","status-publish","format-standard","hentry","category-programs"],"_links":{"self":[{"href":"https:\/\/ahay.org\/blog\/wp-json\/wp\/v2\/posts\/375","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/ahay.org\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/ahay.org\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/ahay.org\/blog\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/ahay.org\/blog\/wp-json\/wp\/v2\/comments?post=375"}],"version-history":[{"count":4,"href":"https:\/\/ahay.org\/blog\/wp-json\/wp\/v2\/posts\/375\/revisions"}],"predecessor-version":[{"id":14924,"href":"https:\/\/ahay.org\/blog\/wp-json\/wp\/v2\/posts\/375\/revisions\/14924"}],"wp:attachment":[{"href":"https:\/\/ahay.org\/blog\/wp-json\/wp\/v2\/media?parent=375"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/ahay.org\/blog\/wp-json\/wp\/v2\/categories?post=375"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/ahay.org\/blog\/wp-json\/wp\/v2\/tags?post=375"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}