CDF2MAT Automated SCRIPT to import NETCDF files to MATLAB | RESAMPLING added to correct RESHAPE for non-integer MS acquisition rates in GCxGC-MS data

Function name \"cdf2mat\" Please use this function to open MS-based chromatographic data from NETCDF (*.CDF) files. Resampling included for non-integer acquisition rates. Outputs nominal mass. Script optimized to process data from comprehensive two-dimensional gas chromatography coupled to mass spectrometry (GCxGC-MS). Updated to remove negative noise signal. INPUT file: Opens the netCDF like 'Sample01.CDF' rate_MS: Desired integer acquisition rate OUTPUT FullMS Full MS chromatogram (second order data tensor) axis_min Retention time axis in minutes axis_mz m/z axis in Daltons I/O: [TIC,FullMS,axis_min,axis_mz] = cdf2mat(file,rate_MS) Compiled with MATLAB R2021b (v.9.11.0.1809720). Requires the Signal Processing Toolbox (v.9.0). Based on netCDFload.m (Murphy, Wenig, Parcsi, Skov e Stuetz) e de iCDF_load (Skov e Bro 2008). K.R. Murphy, P. Wenig, G. Parcsi, T. Skov, R.M. Stuetz (in press) Characterizing odorous emissions using new software for identifying peaks in chemometric models of GC-MS datasets. Chem Intel Lab Sys. doi: 10.1016/j.chemolab.2012.07.006 Skov T and Bro R. (2008) Solving fundamental problems in chromatographic analysis, Analytical and Bioanalytical Chemistry, 390 (1): 281-285. doi: 10.1007/s00216-007-1618-z

函数`cdf2mat`可用于读取NETCDF（*.CDF）格式文件中的基于质谱（Mass Spectrometry, MS）的色谱数据。该函数支持对非整数采集速率的数据进行重采样，可输出标称质量数，其脚本针对全二维气相色谱-质谱联用（Comprehensive Two-dimensional Gas Chromatography coupled to Mass Spectrometry, GCxGC-MS）产生的数据集进行了优化，近期更新已移除负噪声信号。

**输入参数**：
- `file`：读取指定的netCDF格式文件，例如`Sample01.CDF`
- `rate_MS`：期望的整数型采集速率

**输出参数与调用格式**：
标准调用格式为 `[TIC,FullMS,axis_min,axis_mz] = cdf2mat(file,rate_MS)`，各返回值说明如下：
- `TIC`：总离子流色谱图（Total Ion Current, TIC）
- `FullMS`：完整质谱色谱图（二阶数据张量）
- `axis_min`：以分钟为单位的保留时间轴
- `axis_mz`：以道尔顿（Daltons）为单位的质荷比（m/z）轴

本函数基于MATLAB R2021b（版本9.11.0.1809720）编译，需依赖信号处理工具箱（Signal Processing Toolbox，版本9.0）。

本函数基于`netCDFload.m`（Murphy、Wenig、Parcsi、Skov与Stuetz）以及`iCDF_load`（Skov与Bro，2008年）开发，相关引用文献如下：
1. K.R. Murphy, P. Wenig, G. Parcsi, T. Skov, R.M. Stuetz. 利用GC-MS数据集化学计量学模型峰识别新软件表征气味排放[J]. *Chem Intel Lab Sys*, 已刊印, DOI: 10.1016/j.chemolab.2012.07.006
2. Skov T, Bro R. 色谱分析中基础问题的解决方法[J]. *Analytical and Bioanalytical Chemistry*, 2008, 390(1): 281-285. DOI: 10.1007/s00216-007-1618-z