Abstract
Factorial experiments are well-understood when the given observations are outcomes of random variables. However, when we observe spatial point patterns in each combination of factors cells, the methodology is much less developed. Motivated by a real problem of locations of bubbles in a mineral flotation experiment where the interest is analysing if the spatial distribution might be affected by frother concentrations and volumetric airflow rates, we develop an approach for statistical testing of two-way factorial experiments for spatial point patterns. We describe the point patterns through the K-function, a second-order summary statistic, and develop a set of new Fisher-based statistics using weighted means. For inference by Monte Carlo, we use random permutations of weighted residuals depending on the null hypothesis. We conduct simulation experiments to demonstrate the performance of the new test statistics and present the results of the real problem.
Original language | English (US) |
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Pages (from-to) | 1046-1075 |
Number of pages | 30 |
Journal | Test |
Volume | 30 |
Issue number | 4 |
DOIs | |
State | Published - Dec 2021 |
Bibliographical note
Funding Information:We are indebted to Dr Aila Särkkä and Dr Edith Gabriel for their careful comments on an earlier draft. We would like to thank Project CORFO, SMI-ICE-CHILE 13CE12-21844-F1-L1-P3, “Frother Roles Characterization in a Laboratory Mechanical Flotation Cell”, for their kindness in providing the data set analysed. Jonatan A. González and Jorge Mateu are partially funded by Grant MTM2016-78917-R from the Spanish Ministry of Science and Education. Bernardo Lagos-Álvarez thanks VRID Grant 216.014.026-1.0, from University of Concepción.
Funding Information:
We are indebted to Dr Aila Särkkä and Dr Edith Gabriel for their careful comments on an earlier draft. We would like to thank Project CORFO, SMI-ICE-CHILE 13CE12-21844-F1-L1-P3, “Frother Roles Characterization in a Laboratory Mechanical Flotation Cell”, for their kindness in providing the data set analysed. Jonatan A. González and Jorge Mateu are partially funded by Grant MTM2016-78917-R from the Spanish Ministry of Science and Education. Bernardo Lagos-Álvarez thanks VRID Grant 216.014.026-1.0, from University of Concepción.
Publisher Copyright:
© 2021, Sociedad de Estadística e Investigación Operativa.
Keywords
- Flotation bubble data
- Frother concentration
- K-function
- Permutation test
- Replicated point patterns
- Volumetric airflow rate
ASJC Scopus subject areas
- Statistics and Probability
- Statistics, Probability and Uncertainty