added range groundtruth

docs/data_tools.md

@@ -8,9 +8,17 @@ wget ftp://ftp.irisa.fr/local/texmex/corpus/sift.tar.gz
 tar -xf sift.tar.gz
 ```
 
+You then need to convert two of the datasets from the .fvecs format to the binary format as follows:
+
+```bash
+make vec_to_bin
+./vec_to_bin float ../data/sift/sift_learn.fvecs ../data/sift/sift_learn.fbin
+./vec_to_bin float ../data/sift/sift_query.fvecs ../data/sift/sift_query.fbin
+```
+
 ## Compute Groundtruth
 
-ParlayANN supports computing the exact groundtruth for k-nearest neighbors for bin files and fvecs files. The commandline for computing the groundtruth takes the following parameters:
+ParlayANN supports computing the exact groundtruth for k-nearest neighbors for bin files files. The commandline for computing the groundtruth takes the following parameters:
 1. **-base_path**: pointer to the base file, which ground truth will be calculate with respect to.
 2. **-query_path**: pointer to the query file, for which the ground truth will be calculated.
 3. **-data_type**: type of the query and base files. Current options are "uint8", "int8", and "float".
@@ -25,6 +33,25 @@ make compute_groundtruth
 ./compute_groundtruth -base_path ../data/sift/sift_learn.fbin -query_path ../data/sift/sift_query.fbin -data_type float -k 100 -dist_func Euclidian -gt_path ../data/sift/sift-100K
 ```
 
+## Compute Range Groundtruth
+
+We also support computing groundtruth for range search, i.e. finding all points in a given radius. The commandline takes the following parameters:
+1. **-base_path**: pointer to the base file, which ground truth will be calculate with respect to.
+2. **-query_path**: pointer to the query file, for which the ground truth will be calculated.
+3. **-data_type**: type of the query and base files. Current options are "uint8", "int8", and "float".
+4. **-rad**: the radius for which to calculate the groundtruth.
+5. **-dist_func**: the distance function to use when computing the ground truth. Current options are "euclidian" for Euclidian distance and "mips" for maximum inner product.
+6. **-gt_path**: the path where the new groundtruth file will be written
+
+An example commandline is as follows:
+
+```bash
+make compute_range_groundtruth
+./compute_groundtruth -base_path ../data/sift/sift_learn.fbin -query_path ../data/sift/sift_query.fbin -data_type float -rad 5000 -dist_func Euclidian -gt_path ../data/sift/sift-100K-range
+```
+
+The range groundtruth is written in binary format in integers. It consists of first the number of datapoints, followed by the total number of range results for the whole dataset, followed by the number of results for each individual point, followed by the result ids. 
+
 ## File Conversion
 
 ParlayANN supports converting a .vecs file to a .bin file for vectors with `float`, `uint8`, and `int` coordinates. An example commandline: