{
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"source": [
"# FITS_tutorial3\n",
"Open a FITS file and retrieve the first plane of the image array\n",
"as a TImage object.\n",
"\n",
"\n",
"\n",
"\n",
"**Author:** Claudi Martinez \n",
"This notebook tutorial was automatically generated with ROOTBOOK-izer from the macro found in the ROOT repository on Tuesday, May 19, 2026 at 08:13 PM."
]
},
{
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"id": "516392e6",
"metadata": {},
"source": [
"We open a FITS file that contains several image\n",
"extensions. The primary HDU contains no data.\n",
"Data copyright: NASA"
]
},
{
"cell_type": "markdown",
"id": "fbe31ef3",
"metadata": {},
"source": [
"Open extensions 1 to 5 from file"
]
},
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"id": "0ebfaaa9",
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"execution": {
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"shell.execute_reply": "2026-05-19T20:13:56.895902Z"
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"outputs": [
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"name": "stderr",
"output_type": "stream",
"text": [
"Info in : The selected HDU contains an Image Extension\n",
"Info in : The selected HDU contains an Image Extension\n",
"Info in : The selected HDU contains an Image Extension\n",
"Info in : The selected HDU contains an Image Extension\n",
"Info in : The selected HDU contains an Image Extension\n"
]
}
],
"source": [
"TString dir = gROOT->GetTutorialDir();\n",
"\n",
"auto c = new TCanvas(\"c1\", \"FITS tutorial #1\", 800, 700);\n",
"c->Divide(2, 3);\n",
"for (auto i : ROOT::TSeqI(1, 6)) {\n",
" TFITSHDU hdu(dir + \"/io/fitsio/sample3.fits\", i);\n",
"\n",
" TImage* im = (TImage *)hdu.ReadAsImage(0);\n",
" c->cd(i);\n",
" im->Draw();\n",
"}"
]
},
{
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"id": "79f78b22",
"metadata": {},
"source": [
"Draw all canvases "
]
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"gROOT->GetListOfCanvases()->Draw()"
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