Return-Path: X-Original-To: apmail-commons-issues-archive@minotaur.apache.org Delivered-To: apmail-commons-issues-archive@minotaur.apache.org Received: from mail.apache.org (hermes.apache.org [140.211.11.3]) by minotaur.apache.org (Postfix) with SMTP id 3276817E74 for ; Wed, 8 Oct 2014 03:06:35 +0000 (UTC) Received: (qmail 46997 invoked by uid 500); 8 Oct 2014 03:06:34 -0000 Delivered-To: apmail-commons-issues-archive@commons.apache.org Received: (qmail 46636 invoked by uid 500); 8 Oct 2014 03:06:34 -0000 Mailing-List: contact issues-help@commons.apache.org; run by ezmlm Precedence: bulk List-Help: List-Unsubscribe: List-Post: List-Id: Reply-To: issues@commons.apache.org Delivered-To: mailing list issues@commons.apache.org Received: (qmail 46623 invoked by uid 99); 8 Oct 2014 03:06:34 -0000 Received: from arcas.apache.org (HELO arcas.apache.org) (140.211.11.28) by apache.org (qpsmtpd/0.29) with ESMTP; Wed, 08 Oct 2014 03:06:34 +0000 Date: Wed, 8 Oct 2014 03:06:34 +0000 (UTC) From: "Hank Grabowski (JIRA)" To: issues@commons.apache.org Message-ID: In-Reply-To: References: Subject: [jira] [Updated] (MATH-1138) BicubicSplineInterpolator is returning incorrect interpolated values MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit X-JIRA-FingerPrint: 30527f35849b9dde25b450d4833f0394 [ https://issues.apache.org/jira/browse/MATH-1138?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ] Hank Grabowski updated MATH-1138: --------------------------------- Attachment: MATH-1138_patch.diff Patch for this incident > BicubicSplineInterpolator is returning incorrect interpolated values > -------------------------------------------------------------------- > > Key: MATH-1138 > URL: https://issues.apache.org/jira/browse/MATH-1138 > Project: Commons Math > Issue Type: Bug > Affects Versions: 3.3 > Reporter: Adam Bedrossian > Attachments: Interpolated Values from CM and MatLab.docx, MATH-1138_patch.diff > > > I have encountered a use case with the BicubicSplineInterpolator where the interpolated values that are being returned seem incorrect. Furthermore, the values do not match those generated by MatLab using the interp2 'cubic' method. > Here is a snippet of code that uses the interpolator: > double[] xValues = new double[] {36, 36.001, 36.002}; > double[] yValues = new double[] {-108.00, -107.999, -107.998}; > double[][] fValues = new double[][] {{1915, 1906, 1931}, > {1877, 1889, 1894}, > {1878, 1873, 1888}}; > BicubicSplineInterpolator interpolator = new BicubicSplineInterpolator(); > BicubicSplineInterpolatingFunction interpolatorFunction = interpolator.interpolate(xValues, yValues, fValues); > double[][] results = new double[9][9]; > double x = 36; > int arrayIndexX = 0, arrayIndexY = 0; > while(x <= 36.002) { > double y = -108; > arrayIndexY = 0; > while (y <= -107.998) { > results[arrayIndexX][arrayIndexY] = interpolatorFunction.value(x, y); > System.out.println(results[arrayIndexX][arrayIndexY]); > y = y + 0.00025; > arrayIndexY++; > } > x = x + 0.00025; > arrayIndexX++; > } > Attached is a grid showing x and y values and the corresponding interpolated value from both commons math and MatLab. > The values produced by commons math are far off from those created by MatLab. -- This message was sent by Atlassian JIRA (v6.3.4#6332)