Load Project and Fit: LBCO, HRPT¶

This is the most minimal example of using EasyDiffraction. It shows how to load a previously saved project from a directory and run refinement — all in just a few lines of code.

For this example, constant-wavelength neutron powder diffraction data for La0.5Ba0.5CoO3 from HRPT at PSI is used.

It does not contain any advanced features or options, and includes no comments or explanations — these can be found in the other tutorials.

🛠️ Import Library¶

In [2]:

import easydiffraction as edi

import easydiffraction as edi

📂 Load Project¶

Locate Project¶

Download and extract the saved project from the EasyDiffraction data repository.

In [3]:

project_dir = edi.download_data('proj-lbco-hrpt', destination='projects')

project_dir = edi.download_data('proj-lbco-hrpt', destination='projects')

Getting data...

Data 'proj-lbco-hrpt': La0.5Ba0.5CoO3, HRPT (PSI), 300 K

✅ Data 'proj-lbco-hrpt' downloaded and extracted to '../../../projects/proj-lbco-hrpt-69567a192590'

Load Project¶

In [4]:

project = edi.Project.load(project_dir)

project = edi.Project.load(project_dir)

Re-save the project to a fresh working directory so fitting below writes there instead of the bundled read-only copy.

In [5]:

project.save_as(dir_path='projects/load-and-fit-lbco-hrpt')

project.save_as(dir_path='projects/load-and-fit-lbco-hrpt')

Saving project 📦 'lbco_hrpt' to '../../../projects/load-and-fit-lbco-hrpt'

├── 📄 project.edi

├── 📁 structures/

│   └── 📄 lbco.edi

├── 📁 experiments/

│   └── 📄 hrpt.edi

├── 📁 analysis/

│   └── 📄 analysis.edi

└── 📁 reports/

    └── 📄 lbco_hrpt.html

🚀 Perform Analysis¶

Display Structure¶

In [6]:

project.display.structure(struct_name='lbco')

project.display.structure(struct_name='lbco')

Structure 🧩 'lbco' (Atom view type: 'covalent')

Loading plot…

drag = rotate
wheel = zoom
right-drag = pan

Run Fitting¶

In [7]:

project.analysis.fit()

project.analysis.fit()

Standard fitting

📋 Using experiment 🔬 'hrpt' for 'single' fitting

🚀 Starting fit process with 'lmfit (leastsq)'...

📈 Goodness-of-fit progress:

	iteration	time (s)	χ²	change / status
1	1	0.05	1.27
2	45	2.18	1.26

🏆 Best goodness-of-fit (reduced χ²) is 1.26 at iteration 24

✅ Fitting complete.

Saving project 📦 'lbco_hrpt' to '../../../projects/load-and-fit-lbco-hrpt'

├── 📄 project.edi

├── 📁 structures/

│   └── 📄 lbco.edi

├── 📁 experiments/

│   └── 📄 hrpt.edi

├── 📁 analysis/

│   └── 📄 analysis.edi

└── 📁 reports/

    └── 📄 lbco_hrpt.html

Display Fit Results¶

In [8]:

project.display.fit.results()

project.display.fit.results()

⚙️ Settings used:

	Name	Value	Description
1	max_iterations	1000	Maximum solver iterations.

📋 Least-squares fit results:

	Metric	Value
1	🧪 Minimizer	lmfit
2	✅ Overall status	success
3	⏱️ Fitting time (seconds)	2.18
4	🔁 Iterations	42
5	📏 Goodness-of-fit (reduced χ²)	1.26
6	📏 R-factor (Rf, %)	5.57
7	📏 R-factor squared (Rf², %)	5.26
8	📏 Weighted R-factor (wR, %)	4.46

📈 Refined parameters:

	datablock	category	entry	parameter	units	start	value	s.u.	change
1	lbco	cell		length_a	Å	3.8908	3.8908	0.0000	0.00 % ↓
2	lbco	atom_site	La	adp_iso	Ų	0.4920	0.4634	0.0268	5.82 % ↓
3	lbco	atom_site	Co	adp_iso	Ų	0.2490	0.2924	0.0482	17.41 % ↑
4	lbco	atom_site	O	adp_iso	Ų	1.4040	1.4063	0.0159	0.17 % ↑
5	hrpt	linked_structure	lbco	scale		9.1280	9.1076	0.0548	0.22 % ↓
6	hrpt	peak		broad_gauss_u	deg²	0.0803	0.0807	0.0031	0.44 % ↑
7	hrpt	peak		broad_gauss_v	deg²	-0.1125	-0.1138	0.0067	1.13 % ↑
8	hrpt	peak		broad_gauss_w	deg²	0.1195	0.1197	0.0032	0.17 % ↑
9	hrpt	peak		broad_lorentz_y	deg	0.0836	0.0842	0.0021	0.75 % ↑
10	hrpt	instrument		twotheta_offset	deg	0.6205	0.6194	0.0008	0.17 % ↓
11	hrpt	background	1	intensity		166.9200	166.9137	0.8922	0.00 % ↓
12	hrpt	background	2	intensity		167.6100	167.6764	0.6899	0.04 % ↑
13	hrpt	background	3	intensity		172.8800	172.6639	0.7114	0.13 % ↓
14	hrpt	background	4	intensity		180.9200	181.0553	0.8746	0.07 % ↑
15	hrpt	background	5	intensity		168.7000	162.6311	1.2441	3.60 % ↓

• start = parameter value before refinement
• value = refined value from least-squares minimization
• s.u. = standard uncertainty (one sigma), from the covariance matrix
• change = relative change from start, in %; ↑ = increase, ↓ = decrease

In [9]:

project.display.fit.correlations()

project.display.fit.correlations()

Loading plot…

In [10]:

project.display.pattern(expt_name='hrpt')

project.display.pattern(expt_name='hrpt')

Loading plot…

💾 Save Project¶

In [11]:

project.save_as(dir_path='projects/load-and-fit-lbco-hrpt')

project.save_as(dir_path='projects/load-and-fit-lbco-hrpt')

Saving project 📦 'lbco_hrpt' to '../../../projects/load-and-fit-lbco-hrpt'

├── 📄 project.edi

├── 📁 structures/

│   └── 📄 lbco.edi

├── 📁 experiments/

│   └── 📄 hrpt.edi

├── 📁 analysis/

│   └── 📄 analysis.edi

└── 📁 reports/

    └── 📄 lbco_hrpt.html