Data for: Above-ground dry mass and fruit geometries of 31 field muskmelon plants

We collected a total of 751 fruits from 31 Cucumis melo L. var. agrestis Naud. plants, digitized the side profiles of these fruits, and applied an explicit re-expression of Preston’s equation (referred to as EPE hereinafter) to fit the planar coordinates of each fruit profile. By using the estimated parameters, we calculated the volume and surface area of each fruit. The black_white.zip file saves the black and white .bmp images at 600 dpi for the 751 fruits profiles. The edge_data.zip file includes the planar coordinates of each of the 751 fruits, and the EPE results.csv file includes the estimated parameters and goodness-of-fit of the EPE, and the fruit surface area and volume calculated by the surface area and volume formulas of the solid of revolution based on the EPE for each fruit. In addition, the EPE results.csv file also provides the measured volumes of the 751 fruits using the graduated cylinders. The MPG.csv file includes the total leaf dry mass, total stem dry mass, and total fruit volume of 31 C. melo var. Agrestis plants.

Methods
A total of 751 fruits from 31 Cucumis melo L. var. agrestis Naud. plants were collected for detailed study. Each fruit was photographed using a horizontal smartphone (iPhone 12, Zhengzhou, China), mounted on an adjustable tabletop phone mount, while placing the fruit on a test tube rack directly beneath the camera to ensure that the fruits were stably positioned horizontally and that the lens was focused on the fruit's center. To calibrate the deviation of the image size of each fruit from its actual size, we measured the maximum length of the fruit using a vernier caliper.

To obtain the planar coordinates of fruit 2D profiles, the photographs were converted into black-white images and saved as .bmp format using Adobe Photoshop CS2 (version 9.0; Adobe, San Jose, CA, USA). A program developed by Shi et al. (2018) and Su et al. (2019) developed in Matlab (version >= 2009a; MathWorks, Natick, MA, USA) was then used to extract the planar coordinates of each fruit profile from the corresponding .bmp black-white image.The function ‘fitEPE’ in the package ‘biogeom’ (version 1.3.5) (Shi et al., 2022) in R (version 4.2.1) (R Core Team, 2022) was used to estimate the numerical values of a, b, c1, c2, and c3. The Nelder-Mead optimization method was used to minimize the residual sum of squares (RSS) between the observed and predicted y-values of C. melo var. agrestis fruit profiles. After obtaining the estimated parameters of the EPE, we used the surface area and volume equations for the solid of revolution (Narushin et al., 2022) based on the EPE to calculate the fruit surface area and volume for each fruit of the 751 fruits.

To compare the predicted volume of a fruit with its observed volume, we measured volume by submerging each fruit in water in a 100 mL graduated cylinder with a diameter of 3 cm and reading the observed volume of displaced water. The results were saved in the EPE_results.csv file.

The above contents were cited from He et al. (2023).

References

Narushin, V.G.; Romanov, M.N.; Griffin, D.K. Egg and math: Introducing a universal formula for egg shape. Ann. N. Y. Acad. Sci. 2021, 1505, 169–177.
R Core Team. R: A Language and Environment for Statistical Computing; R Foundation for Statistical Computing: Vienna, Austria, 2022. Available online: https://www.r-project.org/ (accessed on 1 June 2022).
Shi, P.; Gielis, J.; Niklas, K.J. Comparison of a universal (but complex) model for avian egg shape with a simpler model. Ann. N. Y. Acad. Sci. 2022, 1514, 34–42.
Shi, P.; Ratkowsky, D.A.; Li, Y.; Zhang, L.; Lin, S.; Gielis, J. A general leaf area geometric formula exists for plants—Evidence from the simplified Gielis equation. Forests 2018, 9, 714.
Su, J.; Niklas, K.J.; Huang, W.; Yu, X.; Yang, Y.; Shi, P. Lamina shape does not correlate with lamina surface area: An analysis based on the simplified Gielis equation. Glob. Ecol. Conserv. 2019, 19, e00666.
He, K.; Hui, C.; Yao, W.; Wang, J.; Wang, L.; Li, Q.; Shi, P. Evidence that field muskmelon (Cucumis melo L. var. agrestis Naud.) fruits are solids of revolution. Plants 2023, in press.

### 数据集说明
我们从31株马泡瓜（*Cucumis melo L. var. agrestis Naud.*）植株上共采集了751枚果实，对这些果实的侧面轮廓进行数字化处理，并采用普雷斯顿方程（Preston’s equation）的显式重表达形式（下文简称EPE）拟合每枚果实轮廓的平面坐标。基于拟合得到的参数，我们计算了每枚果实的体积与表面积。`black_white.zip`文件存储了751枚果实轮廓的600 dpi黑白.bmp图像；`edge_data.zip`文件包含751枚果实各自的平面坐标；`EPE results.csv`文件则包含EPE的拟合参数、拟合优度，以及基于EPE通过旋转体（solid of revolution）表面积与体积公式计算得到的每枚果实的表面积和体积。此外，`EPE results.csv`文件还提供了通过量筒（graduated cylinder）法测得的751枚果实的实测体积。`MPG.csv`文件包含31株马泡瓜植株的总叶片干重、总茎干重及果实总体积。

## 研究方法
本研究共采集31株马泡瓜植株的751枚果实开展详细分析。采用固定于可调式桌面手机支架的横向拍摄智能手机（iPhone 12，中国郑州）进行果实拍照，将果实置于镜头正下方的试管架上，以确保果实稳定水平放置且镜头对准果实中心。为校正果实图像尺寸与实际尺寸的偏差，我们使用游标卡尺测量了每枚果实的最大长度。

为获取果实二维轮廓的平面坐标，我们使用Adobe Photoshop CS2（版本9.0；美国加利福尼亚州圣何塞市Adobe公司）将照片转换为黑白图像并保存为.bmp格式。随后，使用Shi等人（2018）与Su等人（2019）基于Matlab（版本≥2009a；美国马萨诸塞州内蒂克市MathWorks公司）开发的程序，从对应.bmp黑白图像中提取每枚果实轮廓的平面坐标。我们通过R语言（版本4.2.1；R核心团队，2022）中`biogeom`包（版本1.3.5；Shi等人，2022）的`fitEPE`函数，估计参数*a*、*b*、*c1*、*c2*、*c3*的数值。采用内尔德-米德（Nelder-Mead）优化方法最小ize马泡瓜果实轮廓观测*y*值与预测*y*值之间的残差平方和（residual sum of squares, RSS）。得到EPE的拟合参数后，我们基于EPE，通过旋转体表面积与体积公式（Narushin等人，2022）计算751枚果实各自的表面积与体积。

为对比果实预测体积与实测体积，我们采用排水法测量果实体积：将每枚果实浸没于直径3 cm的100 mL量筒的水中，读取排出水的体积作为实测体积。相关结果存储于`EPE_results.csv`文件中。

本研究内容引自He等人（2023）的研究。

## 参考文献
1. Narushin, V.G.; Romanov, M.N.; Griffin, D.K. Egg and math: Introducing a universal formula for egg shape. *Ann. N. Y. Acad. Sci.* 2021, 1505, 169–177.
2. R Core Team. *R: A Language and Environment for Statistical Computing*; R Foundation for Statistical Computing: Vienna, Austria, 2022. Available online: https://www.r-project.org/ (accessed on 1 June 2022).
3. Shi, P.; Gielis, J.; Niklas, K.J. Comparison of a universal (but complex) model for avian egg shape with a simpler model. *Ann. N. Y. Acad. Sci.* 2022, 1514, 34–42.
4. Shi, P.; Ratkowsky, D.A.; Li, Y.; Zhang, L.; Lin, S.; Gielis, J. A general leaf area geometric formula exists for plants—Evidence from the simplified Gielis equation. *Forests* 2018, 9, 714.
5. Su, J.; Niklas, K.J.; Huang, W.; Yu, X.; Yang, Y.; Shi, P. Lamina shape does not correlate with lamina surface area: An analysis based on the simplified Gielis equation. *Glob. Ecol. Conserv.* 2019, 19, e00666.
6. He, K.; Hui, C.; Yao, W.; Wang, J.; Wang, L.; Li, Q.; Shi, P. Evidence that field muskmelon (*Cucumis melo L. var. agrestis Naud.*) fruits are solids of revolution. *Plants* 2023, in press.