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GET /api/1.1/patches/23003/?format=api
{ "id": 23003, "url": "https://patchwork.libcamera.org/api/1.1/patches/23003/?format=api", "web_url": "https://patchwork.libcamera.org/patch/23003/", "project": { "id": 1, "url": "https://patchwork.libcamera.org/api/1.1/projects/1/?format=api", "name": "libcamera", "link_name": "libcamera", "list_id": "libcamera_core", "list_email": "libcamera-devel@lists.libcamera.org", "web_url": "", "scm_url": "", "webscm_url": "" }, "msgid": "<20250324170803.103296-3-stefan.klug@ideasonboard.com>", "date": "2025-03-24T17:07:37", "name": "[2/5] libipa: histogram: Fix quantile() calculation for fractional results", "commit_ref": null, "pull_url": null, "state": "accepted", "archived": false, "hash": "5d4becb986887f490566b53ddf6a98cf2016784a", "submitter": { "id": 184, "url": "https://patchwork.libcamera.org/api/1.1/people/184/?format=api", "name": "Stefan Klug", "email": "stefan.klug@ideasonboard.com" }, "delegate": null, "mbox": "https://patchwork.libcamera.org/patch/23003/mbox/", "series": [ { "id": 5077, "url": "https://patchwork.libcamera.org/api/1.1/series/5077/?format=api", "web_url": "https://patchwork.libcamera.org/project/libcamera/list/?series=5077", "date": "2025-03-24T17:07:35", "name": "Fix histogram for some (corner) cases", "version": 1, "mbox": "https://patchwork.libcamera.org/series/5077/mbox/" } ], "comments": "https://patchwork.libcamera.org/api/patches/23003/comments/", "check": "pending", "checks": "https://patchwork.libcamera.org/api/patches/23003/checks/", "tags": {}, "headers": { "Return-Path": "<libcamera-devel-bounces@lists.libcamera.org>", "X-Original-To": "parsemail@patchwork.libcamera.org", "Delivered-To": "parsemail@patchwork.libcamera.org", "Received": [ "from lancelot.ideasonboard.com (lancelot.ideasonboard.com\n\t[92.243.16.209])\n\tby patchwork.libcamera.org (Postfix) with ESMTPS id 2AF6CC3213\n\tfor <parsemail@patchwork.libcamera.org>;\n\tMon, 24 Mar 2025 17:08:21 +0000 (UTC)", "from lancelot.ideasonboard.com (localhost [IPv6:::1])\n\tby lancelot.ideasonboard.com (Postfix) with ESMTP id D266968959;\n\tMon, 24 Mar 2025 18:08:20 +0100 (CET)", "from perceval.ideasonboard.com (perceval.ideasonboard.com\n\t[213.167.242.64])\n\tby lancelot.ideasonboard.com (Postfix) with ESMTPS id D394B68945\n\tfor <libcamera-devel@lists.libcamera.org>;\n\tMon, 24 Mar 2025 18:08:18 +0100 (CET)", "from ideasonboard.com (unknown\n\t[IPv6:2a00:6020:448c:6c00:854:5bc6:b2a7:e242])\n\tby perceval.ideasonboard.com (Postfix) with ESMTPSA id 50E78A8F;\n\tMon, 24 Mar 2025 18:06:32 +0100 (CET)" ], "Authentication-Results": "lancelot.ideasonboard.com; dkim=pass (1024-bit key;\n\tunprotected) header.d=ideasonboard.com header.i=@ideasonboard.com\n\theader.b=\"ehz8lwSq\"; dkim-atps=neutral", "DKIM-Signature": "v=1; a=rsa-sha256; c=relaxed/simple; d=ideasonboard.com;\n\ts=mail; t=1742835992;\n\tbh=rjzPA6Us67ZjTb/h97K3bGEFgnhDfi+yLIZKMoqHl98=;\n\th=From:To:Cc:Subject:Date:In-Reply-To:References:From;\n\tb=ehz8lwSqBj+OUyB8X9cNv07AnpAQtNh7Te3saFBNbFkK27z0u4epv0CSlql/sRbL3\n\tE+hAu54DBE44uXQLCAuyvIKIiWL67SI72xPPTRLwEZOIgs3DuaWa7z//y/OnQvSzAq\n\txvbH2d8aIxN2yWvulEEk/yEW4SdAH8j09ALaxjOg=", "From": "Stefan Klug <stefan.klug@ideasonboard.com>", "To": "libcamera-devel@lists.libcamera.org", "Cc": "Stefan Klug <stefan.klug@ideasonboard.com>", "Subject": "[PATCH 2/5] libipa: histogram: Fix quantile() calculation for\n\tfractional results", "Date": "Mon, 24 Mar 2025 18:07:37 +0100", "Message-ID": "<20250324170803.103296-3-stefan.klug@ideasonboard.com>", "X-Mailer": "git-send-email 2.43.0", "In-Reply-To": "<20250324170803.103296-1-stefan.klug@ideasonboard.com>", "References": "<20250324170803.103296-1-stefan.klug@ideasonboard.com>", "MIME-Version": "1.0", "Content-Transfer-Encoding": "8bit", "X-BeenThere": "libcamera-devel@lists.libcamera.org", "X-Mailman-Version": "2.1.29", "Precedence": "list", "List-Id": "<libcamera-devel.lists.libcamera.org>", "List-Unsubscribe": "<https://lists.libcamera.org/options/libcamera-devel>,\n\t<mailto:libcamera-devel-request@lists.libcamera.org?subject=unsubscribe>", "List-Archive": "<https://lists.libcamera.org/pipermail/libcamera-devel/>", "List-Post": "<mailto:libcamera-devel@lists.libcamera.org>", "List-Help": "<mailto:libcamera-devel-request@lists.libcamera.org?subject=help>", "List-Subscribe": "<https://lists.libcamera.org/listinfo/libcamera-devel>,\n\t<mailto:libcamera-devel-request@lists.libcamera.org?subject=subscribe>", "Errors-To": "libcamera-devel-bounces@lists.libcamera.org", "Sender": "\"libcamera-devel\" <libcamera-devel-bounces@lists.libcamera.org>" }, "content": "The calculation of the frac variable is based solely on integers and\ntherefore results in the fractional part being either 0 or 1.\n\nIn the original code from RaspberryPi this is mitigated by casting the\nnominator to a double. This works for most cases, but fails when q is\nvery small because of the quantization introduced by item being an\ninteger.\n\nFix both issues by doing the full calculation in double.\n\nSigned-off-by: Stefan Klug <stefan.klug@ideasonboard.com>\n---\n src/ipa/libipa/histogram.cpp | 3 ++-\n 1 file changed, 2 insertions(+), 1 deletion(-)", "diff": "diff --git a/src/ipa/libipa/histogram.cpp b/src/ipa/libipa/histogram.cpp\nindex 10e44b54a0cf..c19a4cbbf3cd 100644\n--- a/src/ipa/libipa/histogram.cpp\n+++ b/src/ipa/libipa/histogram.cpp\n@@ -130,7 +130,8 @@ double Histogram::quantile(double q, uint32_t first, uint32_t last) const\n \tif (cumulative_[first + 1] == cumulative_[first])\n \t\tfrac = 0;\n \telse\n-\t\tfrac = (item - cumulative_[first]) / (cumulative_[first + 1] - cumulative_[first]);\n+\t\tfrac = (q * total() - cumulative_[first]) /\n+\t\t (cumulative_[first + 1] - cumulative_[first]);\n \treturn first + frac;\n }\n \n", "prefixes": [ "2/5" ] }