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arXiv 1111.3591astro-ph.CO
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3DEX:三维测量的快速球面傅里叶-贝塞尔分解代码

3DEX: a code for fast spherical Fourier-Bessel decomposition of 3D surveys

B. Leistedt, A. Rassat, A. Refregier, J. -L. Starck

摘要:

高精度宇宙学需要在3D球坐标系中分析大规模的测量,即球面傅里叶-贝塞尔分解。目前的方法是不够的,未来的数据集从广场宇宙学调查。本文的目的是提出一个公共代码的快速球Fourier-Bessel分解,可应用于宇宙学数据或其他科学领域的球坐标系下的3D数据。我们提出了一个等效的制定的球形傅里叶-贝塞尔分解,分离径向和切向计算。我们建议使用现有的像素化方案HEALPix的快速计算的切向模式。3DEX(3D Expansions)是一种用于3D全天空巡天的快速球面傅里叶-贝塞尔分解的公共代码,它利用HEALPix计算切向模式。我们进行测试非常大的模拟,我们比较的精度和计算时间,我们的方法与优化实施的球形傅里叶-贝塞尔原始配方。对于数百万个星系的调查,计算时间减少了4-12倍,这取决于所需的尺度和精度。该公式也适用于球面谐波的预先计算和外部存储,这允许额外的速度改进。3DEX代码可以容纳具有缺失数据的掩蔽区域的数据。3DEX也可以用于其他学科,其中3D数据将在球坐标中进行分析。代码和文档可以从http://ixkael.com/blog/3dex下载。

英文摘要:

High-precision cosmology requires the analysis of large-scale surveys in 3D spherical coordinates, i.e. spherical Fourier-Bessel decomposition. Current methods are insufficient for future data-sets from wide-field cosmology surveys. The aim of this paper is to present a public code for fast spherical Fourier-Bessel decomposition that can be applied to cosmological data or 3D data in spherical coordinates in other scientific fields. We present an equivalent formulation of the spherical Fourier-Bessel decomposition that separates radial and tangential calculations. We propose the use of the existing pixelisation scheme HEALPix for a rapid calculation of the tangential modes. 3DEX (3D EXpansions) is a public code for fast spherical Fourier-Bessel decomposition of 3D all-sky surveys that takes advantage of HEALPix for the calculation of tangential modes. We perform tests on very large simulations and we compare the precision and computation time of our method with an optimised implementation of the spherical Fourier-Bessel original formulation. For surveys with millions of galaxies, computation time is reduced by a factor 4-12 depending on the desired scales and accuracy. The formulation is also suitable for pre-calculations and external storage of the spherical harmonics, which allows for additional speed improvements. The 3DEX code can accommodate data with masked regions of missing data. 3DEX can also be used in other disciplines, where 3D data are to be analysed in spherical coordinates. The code and documentation can be downloaded at http://ixkael.com/blog/3dex.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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