This is nco.info, produced by makeinfo version 7.2 from nco.texi. INFO-DIR-SECTION netCDF START-INFO-DIR-ENTRY * NCO:: User Guide for the netCDF Operator suite END-INFO-DIR-ENTRY This file documents NCO, a collection of utilities to manipulate and analyze netCDF files. Copyright © 1995-2025 Charlie Zender This is the first edition of the ‘NCO User Guide’, and is consistent with version 2 of ‘texinfo.tex’. Permission is granted to copy, distribute and/or modify this document under the terms of the GNU Free Documentation License, Version 1.3 or any later version published by the Free Software Foundation; with no Invariant Sections, no Front-Cover Texts, and no Back-Cover Texts. The license is available online at The original author of this software, Charlie Zender, wants to improve it with the help of your suggestions, improvements, bug-reports, and patches. Charlie Zender (yes, my surname is zender) 3200 Croul Hall Department of Earth System Science University of California, Irvine Irvine, CA 92697-3100  Indirect: nco.info-1: 1118 nco.info-2: 303527 nco.info-3: 616583 nco.info-4: 902366 nco.info-5: 1205326  Tag Table: (Indirect) Node: Top1118 Node: Foreword2818 Node: Summary7984 Node: Introduction8791 Node: Availability9079 Ref: Availability-Footnote-111260 Node: How to Use This guide11672 Node: Compatability13487 Ref: Compatability-Footnote-119033 Ref: Compatability-Footnote-219181 Node: Windows Operating System19387 Ref: Windows Operating System-Footnote-121989 Node: Symbolic Links22230 Node: Libraries24246 Ref: Libraries-Footnote-125405 Node: netCDF2/3/4 and HDF4/5 Support25589 Ref: netCDF2/3/4 and HDF4/5 Support-Footnote-136586 Ref: netCDF2/3/4 and HDF4/5 Support-Footnote-236877 Ref: netCDF2/3/4 and HDF4/5 Support-Footnote-337243 Ref: netCDF2/3/4 and HDF4/5 Support-Footnote-437365 Ref: netCDF2/3/4 and HDF4/5 Support-Footnote-538446 Node: Help Requests and Bug Reports38940 Node: Strategies44149 Node: Philosophy44547 Node: Climate Model Paradigm46085 Node: Temporary Output Files46724 Ref: Temporary Output Files-Footnote-151944 Ref: Temporary Output Files-Footnote-252062 Node: Appending Variables52171 Ref: Appending Variables-Footnote-154264 Ref: Appending Variables-Footnote-254449 Node: Simple Arithmetic and Interpolation54606 Node: Statistics vs Concatenation55361 Ref: Statistics vs Concatenation-Footnote-156576 Ref: Statistics vs Concatenation-Footnote-256853 Node: Concatenation57240 Node: Averaging60916 Node: Interpolating62401 Node: Large Numbers of Files62929 Ref: Large Numbers of Files-Footnote-168926 Node: Large Datasets69262 Node: Memory Requirements72191 Node: Single and Multi-file Operators73642 Ref: Single and Multi-file Operators-Footnote-179431 Node: Memory for ncap279597 Node: Performance81089 Node: Shared features83088 Node: Internationalization84741 Node: Metadata Optimization85325 Node: OpenMP Threading87286 Node: Command Line Options91347 Ref: Command Line Options-Footnote-193844 Node: Truncating Long Options94137 Node: Multi-arguments95833 Ref: Multi-arguments-Footnote-1100418 Node: Sanitization of Input100715 Node: Specifying Input Files103386 Ref: Specifying Input Files-Footnote-1112821 Node: Specifying Output Files113166 Node: Remote storage114963 Ref: Remote storage-Footnote-1120612 Ref: Remote storage-Footnote-2120841 Ref: Remote storage-Footnote-3121195 Node: OPeNDAP121632 Ref: OPeNDAP-Footnote-1128047 Ref: OPeNDAP-Footnote-2128628 Ref: OPeNDAP-Footnote-3129098 Ref: OPeNDAP-Footnote-4129349 Ref: OPeNDAP-Footnote-5129741 Node: Retaining Retrieved Files130006 Node: File Formats and Conversion132270 Node: File Formats133469 Ref: File Formats-Footnote-1137751 Node: Determining File Format137943 Node: File Conversion141504 Ref: File Conversion-Footnote-1143280 Node: Autoconversion143523 Node: Zarr and NCZarr149468 Node: Large File Support153209 Ref: Large File Support-Footnote-1154752 Node: Subsetting Files154790 Ref: Subsetting Files-Footnote-1170379 Node: Subsetting Coordinate Variables170614 Node: Group Path Editing173826 Node: Flattening Groups176008 Node: Moving Groups181148 Ref: Moving Groups-Footnote-1183339 Node: Dismembering Files183528 Node: Checking CF-compliance191673 Ref: Checking CF-compliance-Footnote-1199053 Node: C and Fortran Index Conventions199209 Node: Hyperslabs201016 Node: Stride207797 Node: Record Appending211138 Node: Subcycle214940 Ref: Subcycle-Footnote-1218921 Node: Interleave219031 Node: Multislabs224473 Node: Wrapped Coordinates232425 Node: Auxiliary Coordinates235363 Node: Grid Generation242623 Ref: Grid Generation-Footnote-1270539 Ref: Grid Generation-Footnote-2271001 Node: Regridding271590 Node: Climatology and Bounds Support303527 Node: UDUnits Support307854 Node: Rebasing Time Coordinate317397 Node: Multiple Record Dimensions320454 Node: Missing Values322779 Ref: Missing Values-Footnote-1328715 Ref: Missing Values-Footnote-2328960 Node: Chunking329069 Ref: Chunking-Footnote-1347713 Node: Quantization Algorithms347963 Node: Compression350837 Ref: fgr:qnt_cr_dfl363391 Ref: fgr:qnt_cr_bz2371991 Ref: fgr:qnt_cr_zst374589 Ref: Compression-Footnote-1375626 Ref: Compression-Footnote-2375750 Ref: Compression-Footnote-3375838 Ref: Compression-Footnote-4375934 Ref: Compression-Footnote-5376497 Ref: Compression-Footnote-6376714 Node: Linear Packing376905 Node: Precision-Preserving Compression378454 Ref: Precision-Preserving Compression-Footnote-1405557 Ref: Precision-Preserving Compression-Footnote-2405927 Ref: Precision-Preserving Compression-Footnote-3406349 Ref: Precision-Preserving Compression-Footnote-4407468 Ref: Precision-Preserving Compression-Footnote-5408836 Node: Deflation409034 Node: MD5 digests411279 Node: Buffer sizes415256 Ref: Buffer sizes-Footnote-1416554 Node: RAM disks416678 Node: Unbuffered I/O421691 Node: Packed data422990 Ref: Packed data-Footnote-1430826 Ref: Packed data-Footnote-2431003 Node: Operation Types431230 Node: Type Conversion438950 Node: Automatic type conversion440216 Ref: Automatic type conversion-Footnote-1447026 Ref: Automatic type conversion-Footnote-2447049 Ref: Automatic type conversion-Footnote-3447242 Node: Promoting Single-precision to Double447446 Ref: Promoting Single-precision to Double-Footnote-1466359 Ref: Promoting Single-precision to Double-Footnote-2466824 Ref: Promoting Single-precision to Double-Footnote-3467317 Ref: Promoting Single-precision to Double-Footnote-4467617 Ref: Promoting Single-precision to Double-Footnote-5467722 Node: Manual type conversion467786 Node: Batch Mode468771 Node: Global Attribute Addition469932 Node: History Attribute472451 Ref: History Attribute-Footnote-1476081 Node: File List Attributes476330 Node: CF Conventions478134 Node: ARM Conventions494285 Node: Operator Version496400 Node: Reference Manual497558 Node: ncap2 netCDF Arithmetic Processor498692 Node: Syntax of ncap2 statements504427 Node: Expressions505799 Node: Dimensions513159 Node: Left hand casting515408 Node: Arrays and hyperslabs520253 Node: Attributes526681 Node: Value List530441 Node: Number literals531696 Node: if statement535649 Node: Print & String methods537873 Node: Missing values ncap2542051 Node: Methods and functions547137 Node: RAM variables554429 Node: Where statement555709 Node: Loops561032 Node: Include files562367 Node: Sort methods563591 Node: UDUnits script574948 Node: Vpointer578668 Node: Irregular grids583135 Node: Bilinear interpolation588664 Node: GSL special functions592914 Ref: GSL special functions-Footnote-1615263 Node: GSL interpolation616583 Node: GSL least-squares fitting618663 Node: GSL statistics622718 Node: GSL random number generation626491 Node: Examples ncap2630996 Node: Intrinsic mathematical methods638567 Ref: Intrinsic mathematical methods-Footnote-1643920 Ref: Intrinsic mathematical methods-Footnote-2644779 Node: Operator precedence and associativity644852 Node: ID Quoting647404 Node: make_bounds() function649945 Node: solar_zenith_angle function651189 Node: ncatted netCDF Attribute Editor652551 Ref: ncatted netCDF Attribute Editor-Footnote-1673256 Node: ncbo netCDF Binary Operator674337 Ref: ncbo netCDF Binary Operator-Footnote-1688139 Ref: ncbo netCDF Binary Operator-Footnote-2688328 Ref: ncbo netCDF Binary Operator-Footnote-3688688 Ref: ncbo netCDF Binary Operator-Footnote-4688748 Ref: ncbo netCDF Binary Operator-Footnote-5688820 Ref: ncbo netCDF Binary Operator-Footnote-6689026 Node: ncchecker netCDF Compliance Checker689383 Node: ncclimo netCDF Climatology Generator691447 Ref: ncclimo netCDF Climatology Generator-Footnote-1778718 Ref: ncclimo netCDF Climatology Generator-Footnote-2779129 Ref: ncclimo netCDF Climatology Generator-Footnote-3779396 Node: ncecat netCDF Ensemble Concatenator779706 Node: nces netCDF Ensemble Statistics789344 Ref: nces netCDF Ensemble Statistics-Footnote-1799494 Ref: nces netCDF Ensemble Statistics-Footnote-2799772 Node: ncflint netCDF File Interpolator800295 Node: ncks netCDF Kitchen Sink809149 Ref: ncks netCDF Kitchen Sink-Footnote-1885166 Ref: ncks netCDF Kitchen Sink-Footnote-2885484 Ref: ncks netCDF Kitchen Sink-Footnote-3885855 Node: Filters for ncks885970 Node: ncpdq netCDF Permute Dimensions Quickly902366 Ref: ncpdq netCDF Permute Dimensions Quickly-Footnote-1924399 Ref: ncpdq netCDF Permute Dimensions Quickly-Footnote-2924504 Ref: ncpdq netCDF Permute Dimensions Quickly-Footnote-3925085 Node: ncra netCDF Record Averager925357 Node: ncrcat netCDF Record Concatenator936155 Node: ncremap netCDF Remapper940776 Ref: ncremap netCDF Remapper-Footnote-11093894 Ref: ncremap netCDF Remapper-Footnote-21094305 Ref: ncremap netCDF Remapper-Footnote-31094388 Ref: ncremap netCDF Remapper-Footnote-41094530 Ref: ncremap netCDF Remapper-Footnote-51094856 Ref: ncremap netCDF Remapper-Footnote-61095323 Ref: ncremap netCDF Remapper-Footnote-71095609 Node: ncrename netCDF Renamer1095683 Node: ncwa netCDF Weighted Averager1115405 Ref: ncwa netCDF Weighted Averager-Footnote-11120842 Ref: ncwa netCDF Weighted Averager-Footnote-21120983 Node: Mask condition1121189 Ref: Mask condition-Footnote-11122664 Node: Normalization and Integration1122864 Ref: Normalization and Integration-Footnote-11128669 Ref: Normalization and Integration-Footnote-21128743 Ref: Normalization and Integration-Footnote-31128867 Node: Contributing1129036 Ref: Contributing-Footnote-11129771 Node: Contributors1130185 Node: Citation1134590 Node: Proposals for Institutional Funding1135956 Node: Quick Start1137131 Node: Daily data in one file1137608 Node: Monthly data in one file1139030 Node: One time point one file1140692 Node: Multiple files with multiple time points1141649 Node: CMIP5 Example1142141 Node: Combine Files1144877 Node: Global Distribution of Long-term Average1154331 Ref: fgr:glb1154567 Node: Annual Average over Regions1159342 Ref: fgr:anl1159552 Node: Monthly Cycle1172449 Ref: fgr:mon1172608 Node: Regrid MODIS Data1179672 Node: Add Coordinates to MODIS Data1187232 Node: Permute MODIS Coordinates1189234 Node: Parallel1191171 Node: CCSM Example1191523 Node: mybibnode1205326 Ref: ZeM071205451 Ref: Zen081205682 Ref: WZJ071205890 Ref: ZMW061206276 Ref: ZeW071206516 Ref: WZJ061206931 Ref: WZJ0731207121 Ref: WZJ0741207569 Ref: WZJ0811207771 Ref: WZJ0911208051 Ref: PFT881208269 Node: General Index1208396  End Tag Table  Local Variables: coding: utf-8 End: